delete Cause:

src/server/routes/apiv3/slack-integration-settings.js

@@ -538,7 +538,7 @@ module.exports = (crowi) => {
     const slackBotToken = crowi.configManager.getConfig('crowi', 'slackbot:token');
     const status = await getConnectionStatus(slackBotToken);
     if (status.error != null) {
-      return res.apiv3Err(new ErrorV3(`Error occured while getting connection. Cause: ${status.error}`, 'send-message-failed'));
+      return res.apiv3Err(new ErrorV3(`Error occured while getting connection. ${status.error}`, 'send-message-failed'));
     }
 
     const { channel } = req.body;