fix for Mac when no target map is selected

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@43901 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/gui_modules/gcpmanager.py

@@ -861,12 +861,13 @@ class GCP(MapFrame, wx.Frame, ColumnSorterMixin):
         #
         # show new display & draw map
         #
-        self.MapWindow = self.TgtMapWindow
-        self.Map = self.TgtMap
-        self.OnZoomToMap(None)
         self.MapWindow = self.SrcMapWindow
         self.Map = self.SrcMap
         self.OnZoomToMap(None)
+        if self.show_target:
+            self.MapWindow = self.TgtMapWindow
+            self.Map = self.TgtMap
+            self.OnZoomToMap(None)
 
         #
         # bindings