Indenters: Fix dangling pointer when project settings are deleted.

Task-number: QTCREATORBUG-5390
Change-Id: I68517955a86fbb2ded53f6235a7fe27793e2b2c8
Reviewed-on: http://codereview.qt.nokia.com/1481
Reviewed-by: Tobias Hunger <tobias.hunger@nokia.com>

src/plugins/texteditor/basetexteditor.h

@@ -355,6 +355,8 @@ private slots:
     bool inFindScope(const QTextCursor &cursor);
     bool inFindScope(int selectionStart, int selectionEnd);
     void inSnippetMode(bool *active);
+    void onTabPreferencesDestroyed();
+    void onCodeStylePreferencesDestroyed();
 
 private:
     Internal::BaseTextEditorPrivate *d;