FS-10257: [mod_sofia] libsofia-sip-ua/msg no longer builds on Arch Linux due to -Werror=parentheses

libs/sofia-sip/.update

-Mon Apr 24 12:31:01 CDT 2017
+Mon Jun  5 17:43:45 CDT 2017

libs/sofia-sip/libsofia-sip-ua/msg/msg_parser.c

@@ -2017,7 +2017,7 @@ msg_header_t **serialize_one(msg_t *msg, msg_header_t *h, msg_header_t **prev)
     for (last = h; last->sh_succ; last = last->sh_succ) {
       /* Ensure that chain is connected */
       assert(last->sh_next == last->sh_succ);
-      assert(last->sh_succ->sh_prev = &last->sh_succ);
+      assert(last->sh_succ->sh_prev == &last->sh_succ);
     }
     prev = &last->sh_succ;
   }