Return early if addresses pointer is null

Author: oschwald

extension/maxminddb.c

@@ -242,6 +242,7 @@ static int ip_converter(PyObject *obj, struct sockaddr_storage *ip_address) {
             PyErr_SetString(
                 PyExc_RuntimeError,
                 "getaddrinfo was successful but failed to set the addrinfo");
+            return 0;
         }
         memcpy(ip_address, addresses->ai_addr, addresses->ai_addrlen);
         freeaddrinfo(addresses);