Fix #3810 X/Y Property Update on Locked View

- fixes x/y update when position locked for simple
  Views and ProjectionGroups.

src/Mod/TechDraw/App/DrawViewCollection.h

@@ -52,6 +52,7 @@ public:
     bool isUnsetting(void) { return nowUnsetting; }
 
     int countChildren();
+    void lockChildren(void);
 
     virtual void onDocumentRestored();
     virtual App::DocumentObjectExecReturn *execute(void);