Fix PageCursorProviderImplTest on IBM JVM

Underlying exception : org.mockito.exceptions.base.MockitoException: Could not modify all classes [interface java.lang.Comparable, class org.apache.activemq.artemis.core.paging.impl.Page, class java.lang.Object]

	at org.apache.activemq.artemis.core.paging.cursor.impl.PageCursorProviderImplTest.shouldAllowConcurrentPageReads(PageCursorProviderImplTest.java:48)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:90)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
	at java.lang.reflect.Method.invoke(Method.java:508)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.FailOnTimeout$StatementThread.run(FailOnTimeout.java:74)
Caused by: org.mockito.exceptions.base.MockitoException: Could not modify all classes [interface java.lang.Comparable, class org.apache.activemq.artemis.core.paging.impl.Page, class java.lang.Object]
	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:152)
	at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:365)
	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:174)
	at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:376)
	... 10 more
Caused by: java.lang.instrument.UnmodifiableClassException
	at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
	at sun.instrument.InstrumentationImpl.retransformClasses(InstrumentationImpl.java:163)
	at org.mockito.internal.creation.bytebuddy.InlineBytecodeGenerator.triggerRetransformation(InlineBytecodeGenerator.java:174)
	at org.mockito.internal.creation.bytebuddy.InlineBytecodeGenerator.mockClass(InlineBytecodeGenerator.java:153)
	at org.mockito.internal.creation.bytebuddy.TypeCachingBytecodeGenerator$1.call(TypeCachingBytecodeGenerator.java:37)
	at org.mockito.internal.creation.bytebuddy.TypeCachingBytecodeGenerator$1.call(TypeCachingBytecodeGenerator.java:34)
	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:152)
	at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:365)
	at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:174)
	at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:376)
	at org.mockito.internal.creation.bytebuddy.TypeCachingBytecodeGenerator.mockClass(TypeCachingBytecodeGenerator.java:32)
	at org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker.createMockType(InlineByteBuddyMockMaker.java:197)
	at org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker.createMock(InlineByteBuddyMockMaker.java:178)
	at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:35)
	at org.mockito.internal.MockitoCore.mock(MockitoCore.java:62)
	at org.mockito.Mockito.mock(Mockito.java:1907)
	at org.mockito.Mockito.mock(Mockito.java:1816)
	... 10 more