XSLT server generation for example xml files doesn't work with -Dtest

When testing IT tests that use arquillian, it is very helpful to use -Dtest argument to enable trace for given packages. Unfortunately this isn't applied to example xml files. We need to allow this as well.

https://github.com/infinispan/infinispan/blob/master/server/integration/testsuite/src/test/resources/config/xslt/config-modifier.xsl#L84 and appropriate code needs to be added to examples-modifier.xsl file.