Remove hard-coded disabling of debug logs

Instead, set the default level of all logs to QtWarningMsg.

The call to setFilterRules overrides the user preferences in qtlogging.ini.

Change-Id: Id5f6cd550d14ff7f45ae04c5d3110e0bafb0f072
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/clangcodemodel/clangbackendlogging.cpp

@@ -28,7 +28,7 @@
 namespace ClangCodeModel {
 namespace Internal {
 
-Q_LOGGING_CATEGORY(ipcLog, "qtc.clangcodemodel.ipc")
+Q_LOGGING_CATEGORY(ipcLog, "qtc.clangcodemodel.ipc", QtWarningMsg)
 
 } // namespace Internal
 } // namespace ClangCodeModel