Ox: Improve time stamp parsing.

ox.go

@@ -79,12 +79,9 @@ func oxDecrypt(m xmpp.Chat, client *xmpp.Client, user string,
 	if stamp == nil {
 		return "error", time.Now(), errors.New("Ox: no stamp attribute")
 	}
-	msgStamp, err := time.Parse("2006-01-02T15:04:05Z", stamp.Value)
+	msgStamp, err := time.Parse("2006-01-02T15:04:05Z0700", stamp.Value)
 	if err != nil {
-		msgStamp, err = time.Parse("2006-01-02T15:04:05Z0700", stamp.Value)
-		if err != nil {
-			return "error", time.Now(), err
-		}
+		return "error", time.Now(), err
 	}
 	payload := signcrypt.SelectElement("payload")
 	if payload == nil {