msrp: send failure response after referening the buffer

(cherry picked from commit 5f8adb625b6bae81ef44613d774106bf3a943bb0)
(cherry picked from commit 4ff58bb3e02b76e2489144867c8b0dc5041dc621)
(cherry picked from commit 0f8b36091a64de012377bd2460e299529886a45c)

src/modules/msrp/msrp_cmap.c

@@ -183,8 +183,8 @@ int msrp_cmap_save(msrp_frame_t *mf)
 		LM_DBG("expires is greater than max value\n");
 		xhdrs.len = snprintf(sbuf, MSRP_SBUF_SIZE, "Max-Expires: %d\r\n",
 				msrp_auth_max_expires);
-		msrp_reply(mf, &msrp_reply_423_code, &msrp_reply_423_text, &xhdrs);
 		xhdrs.s = sbuf;
+		msrp_reply(mf, &msrp_reply_423_code, &msrp_reply_423_text, &xhdrs);
 		return -4;
 	}
 	if(msrp_frame_get_first_from_path(mf, &fpeer) < 0) {