Revert "Remove a broken check for GetUpdatesChan."

This was not properly tested and results in the bot looping.

This reverts commit 5f38203a15.

bot.go

@@ -501,9 +501,12 @@ func (bot *BotAPI) GetUpdatesChan(config UpdateConfig) (UpdatesChannel, error) {
 			}
 
 			for _, update := range updates {
+				if update.UpdateID >= config.Offset {
+					config.Offset = update.UpdateID + 1
 					ch <- update
 				}
 			}
+		}
 	}()
 
 	return ch, nil

passport.go

@@ -307,7 +307,7 @@ type (
 		MiddleNameNative     string `json:"middle_name_native"`
 	}
 
-	// IDDocumentData https://core.telegram.org/passport#iddocumentdata
+	// IdDocumentData https://core.telegram.org/passport#iddocumentdata
 	IDDocumentData struct {
 		DocumentNumber string `json:"document_no"`
 		ExpiryDate     string `json:"expiry_date"`