broken event tracing in old perf versions

https://github.com/KDAB/hotspot/blame/6188ec8db6efc2bcdea5f0a8753264a42c57f245/src/recordhost.cpp#L133 added in #520 by @lievenhey seems to have broken event tracing in perf <= 4.19 (from 3.7 on it was included within perf, 4.20 seems to be the first version where the then externalized library is necessary for this).

This effects RHEL8 and other distribution still under maintenance support.

A possible solution may be:

-    capabilities.libtraceeventSupport = buildOptions.contains("libtraceevent: [ on  ]");
+    capabilities.libtraceeventSupport = !buildOptions.contains("libtraceevent:") || 
+            buildOptions.contains("libtraceevent: [ on  ]");;