Merge pull request #3487 from Sigma1912/Gmoccapy_Fix-gtk-warnings-on-mdi-buttons-pagination

Gmoccapy: Fix gtk warnings on mdi buttons (next/previous) pagination

Author: hansu

src/emc/usr_intf/gmoccapy/gmoccapy.py

@@ -847,7 +847,8 @@ def _get_button_with_image(self, name, filepath, icon_name):
 
     def _remove_button(self, dic, box):
         for child in dic:
-            box.remove(dic[child])
+            if dic[child].get_parent():
+                box.remove(dic[child])
 
     def _on_btn_next_clicked(self, widget):
         # remove all buttons from container