QmlDesigner: Do not move cursor when reformating

When saving a .ui.qml file the complete file is reformated.
Without this patch the cursor is moved to the bottom.

The cursor is still moved, but they line is kept.
Since we reformat the complete file this should be fine.

Change-Id: Ia1ef003e2e6ca7497dcad7e0e8044ffb99c80ea3
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmldesigner/components/texteditor/texteditorwidget.h

@@ -57,6 +57,7 @@ public:
     void setStatusText(const QString &text);
     void clearStatusBar();
 
+    int currentLine() const;
 private:
     void updateSelectionByCursorPosition();