Update nemo-python-overview-example.xml (#552)

Author: GooseIndustries

nemo-python/docs/reference/nemo-python-overview-example.xml

@@ -18,7 +18,7 @@ class ColumnExtension(GObject.GObject, Nemo.MenuProvider):
         pass
 
     def menu_activate_cb(self, menu, file):
-        print "menu_activate_cb",file
+        print("menu_activate_cb", file)
 
     def get_file_items(self, window, files):
         if len(files) != 1: