Don't exit with error when source is target for maze router

compiler/router/router.py

@@ -1000,8 +1000,7 @@ class router(router_tech):
         # Double check source and taget are not same node, if so, we are done!
         for k, v in self.rg.map.items():
             if v.source and v.target:
-                debug.error("Grid cell is source and target! {}".format(k))
-                return False
+                return True
 
         # returns the path in tracks
         (path, cost) = self.rg.route(detour_scale)