Prevent "Invalid URL" errors due to trailing spaces when editing Slack Webhook URL (#925)
Prevent "Invalid URL" errors due to trailing spaces when editing Slack Webhook URL (#925)

no issue
- trim the slack URL in the `updateURL` action
TryGhost/Ghost-Admin,acburdine/Ghost-Admin,kevinansfield/Ghost-Admin,kevinansfield/Ghost-Admin,acburdine/Ghost-Admin,TryGhost/Ghost-Admin