cups: initialize thread running member

Change-Id: Idf8b079857638558075fa6b1fb5f7ea6b3c9f632

vcl/unx/generic/printer/cupsmgr.cxx

@@ -193,7 +193,8 @@ CUPSManager::CUPSManager() :
         PrinterInfoManager( CUPS ),
         m_nDests( 0 ),
         m_pDests( NULL ),
-        m_bNewDests( false )
+        m_bNewDests( false ),
+        m_bPPDThreadRunning( false )
 {
     m_aDestThread = osl_createThread( run_dest_thread_stub, this );
 }