Fix error messages in telegram and slack bridges

bridge/slack/handlers.go

@@ -80,7 +80,7 @@ func (b *Bslack) handleSlackClient(messages chan *config.Message) {
 		case *slack.FileDeletedEvent:
 			rmsg, err := b.handleFileDeletedEvent(ev)
 			if err != nil {
-				b.Log.Errorf("%#v", err)
+				b.Log.Printf("%#v", err)
 				continue
 			}
 			messages <- rmsg

bridge/telegram/handlers.go

@@ -176,7 +176,7 @@ func (b *Btelegram) handleRecv(updates <-chan tgbotapi.Update) {
 
 		if update.Message == nil && update.ChannelPost == nil &&
 			update.EditedMessage == nil && update.EditedChannelPost == nil {
-			b.Log.Error("Getting nil messages, this shouldn't happen.")
+			b.Log.Info("Received event without messages, skipping.")
 			continue
 		}