Slack Integration not working alongide BeanStalk plugin. #22

Please, do not create duplicate issues

Actual behaviour

I have been using the slack integration to receive notifications on discord. Once I installed Beanstalk this function seized to work.
Simply put the web hook does not post any notifications.

Expected behaviour

To have Beanstalk installed alongside the slack integration whilst providing the beanstalk performance improvement and recieving notifications through the slack integration.

Steps to reproduce

1. Install Beanstalk using the following guide: https://github.com/kanboard/plugin-beanstalk (No Docker)
2. Install Slack using the following guide: https://github.com/kanboard/plugin-slack
3. add a /slack suffix to the webhook so to make slack compatibel with discord.

Configuration

• Plugin version: Slack: V1.0.7. BeanStalk: V1.0.0
• Kanboard version: V1.2.22
• Database type and version: mysql ver 15.1 Distrib 10.3.28-MariaDB
• PHP version: 8.0.17
• OS: CentOS-8
• Browser: Firefox