fix CommonMessaging::outputLevel()

See merge request !154

GaudiKernel/GaudiKernel/CommonMessaging.h

@@ -139,7 +139,7 @@ public:
   }
 
   /// Backward compatibility function for getting the output level
-  inline MSG::Level outputLevel() const __attribute__ ((deprecated)) { return m_level; }
+  inline MSG::Level outputLevel() const __attribute__ ((deprecated)) { return msgLevel(); }
 
   /// get the output level from the embedded MsgStream
   inline bool msgLevel(MSG::Level lvl) const { return UNLIKELY(msgLevel() <= lvl); }