The commit d4ae04a7 has changed #define of HAVE_XMLRPCLCIENT
to #cmakedefine01 - since HAVE_XMLRPCCLIENT is not defined anywhere
in the CMakeFiles.txt, this lead to the 'Report bug' button being
unconditionally disabled at compile time.
Since KXmlRpcClient is a REQUIRED dependency (and has been for a while),
we can just remove the macro altogether.