REST API 1.9.1 null pointer exception is raised when you try to create a new group without members or admins

Hello,

We use the > POST /groups endpoint in order to create groups. In most cases groups initially does not have members and admins. As far as I know, admins and members parameters are optional. However, at the latest version if you do not include them at your payload you receive an Internal server error response. I am sending you the payload and the exception from server logs.

OpenFire version 4.7.3
REST API 1.9.1

{
  "name": "001",
  "description": "test",
  "shared": true
}
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311) [jetty-io-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105) [jetty-io-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104) [jetty-io-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:386) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034) [jetty-util-9.4.43.v20210629.jar:9.4.43.v20210629]
    at java.lang.Thread.run(Thread.java:829) [?:?]
Caused by: java.lang.NullPointerException
    at org.jivesoftware.openfire.plugin.rest.controller.GroupController.createGroup(GroupController.java:111) ~[?:?]
    at org.jivesoftware.openfire.plugin.rest.service.GroupService.createGroup(GroupService.java:72) ~[?:?]
    at jdk.internal.reflect.GeneratedMethodAccessor203.invoke(Unknown Source) ~[?:?]
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
    at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
    at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52) ~[?:?]
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:134) ~[?:?]
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:177) ~[?:?]
    at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:176) ~[?:?]
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:81) ~[?:?]
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:475) ~[?:?]
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:397) ~[?:?]
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:81) ~[?:?]
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:255) ~[?:?]
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248) ~[?:?]
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244) ~[?:?]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:292) ~[?:?]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:274) ~[?:?]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:244) ~[?:?]
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:265) ~[?:?]
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:234) ~[?:?]
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:684) ~[?:?]
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:394) ~[?:?]