test: Remove REJECT message code

test/functional/test_framework/mininode.py

@@ -339,7 +339,6 @@ class P2PInterface(P2PConnection):
     def on_merkleblock(self, message): pass
     def on_notfound(self, message): pass
     def on_pong(self, message): pass
-    def on_reject(self, message): pass
     def on_sendcmpct(self, message): pass
     def on_sendheaders(self, message): pass
     def on_tx(self, message): pass