path: fix `url.copy` dropping the port

The copy method have been wrong for a while, but the new code reveals it.

mercurial/utils/urlutil.py

@@ -241,7 +241,7 b' class url:'
         u.user = self.user
         u.passwd = self.passwd
         u.host = self.host
-        u.path = self.path
+        u.port = self.port
         u.query = self.query
         u.fragment = self.fragment
         u._localpath = self._localpath