+HeapDumpOnOutOfMemoryError will dump an hprof only for the very first time
an OOME occurs. This is to prevent other threads also to throw OOME at around
the same time ending up with lots of heap dumps.
However, in case an application catches an OOME and continues then it won't
be able to heap dump at a later stage. The idea is to reenable heap dumping
later on after say a few minutes. Of course, preferably configurable.