debugger: fix regression when trying to remove watched expressions

Change-Id: I0d12339ab1903dc78eec699e07fc0c17daab0e5d
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/watchhandler.h

@@ -89,7 +89,6 @@ public:
 
     void cleanup();
     void watchExpression(const QString &exp);
-    void removeWatchExpression(const QString &exp);
     Q_SLOT void clearWatches();
 
     void updateWatchers(); // Called after locals are fetched