AndroidSettingsDialog: Warn the user that spaces in the ndk path are bad

Task-number: QTCREATORBUG-11629
Change-Id: I576940fa5ac3fd47376cf3fc700689e1046387b0
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>

src/plugins/android/androidsettingswidget.h

@@ -103,6 +103,7 @@ private:
 
     State m_sdkState;
     State m_ndkState;
+    QString m_ndkErrorMessage;
     int m_ndkCompilerCount;
     QString m_ndkMissingQtArchs;
     State m_javaState;