AndroidManifestEditor: Be less noisy with changed() signals

Changed signal shouldn't be sent on all contents changes, but only if
the modification state changes.

Change-Id: I2fda12b5ded56eac4eec8cf6a428c04b18b576ec
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/android/androidmanifesteditorwidget.cpp

@@ -507,7 +507,7 @@ bool AndroidManifestEditorWidget::open(QString *errorString, const QString &file
 
 void AndroidManifestEditorWidget::setDirty(bool dirty)
 {
-    if (m_stayClean)
+    if (m_stayClean || dirty == m_dirty)
         return;
     m_dirty = dirty;
     emit guiChanged();