inspector: Prevent looping when picking widgets

What was happening that the button press event that we use
to select a widget caused another clicked signal emission of
the inspect button, starting another pick action.

gtk/inspector/inspect-button.c

@@ -301,7 +301,7 @@ property_query_event (GtkWidget *widget,
         }
     }
 
-  return FALSE;
+  return TRUE;
 }
 
 void