V8Debugger: Remove unused member

Change-Id: Ieaea81203cad0170d638dcee8b91b73bb3bc7144
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/debugger/qml/qmlv8debuggerclient.cpp

@@ -127,7 +127,6 @@ public:
 
     QScriptValue parser;
     QScriptValue stringifier;
-    QStringList scriptSourceRequests;
 
     QHash<int, QString> evaluatingExpression;
     QHash<int, QByteArray> localsAndWatchers;