Hi Norbert, I’m glad you found a workaround!
Lifeboat can’t promise not to overwrite your changes, so I recommend doing the header setup within Lifeboat itself.
To create custom upstream headers create a Forwarding / Reverse Proxy entry. Select a domain (you can unassign the Web App and use the domain here) to enable the rest of the form. Click the Proxy Headers button and add these two entries:
Upgrade: $http_upgrade
Connection: "Upgrade"
Click save to close the Proxy Headers window. Next select the Web App as the source, so click the little disclosure arrow at the end of the “Target URL” field to select your web app. Click Save on the Reverse Proxy config and you’re all set.
Now your changes won’t be lost when making adjustments in Lifeboat.