Add accidentally removed line.

sshuttle/firewall.py

@@ -250,6 +250,7 @@ def main(method_name, syslog):
         try:
             if port_v4:
                 debug2('firewall manager: undoing IPv4 changes.\n')
+            method.setup_firewall(port_v4, 0, [], socket.AF_INET4, [], udp)
         except:
             try:
                 debug1("firewall manager: "