When trying to make an application link it generates an IllegalArgumentException when checking the url. I traced it to the app calling this url https://myhost.dk/fecru/rest/applinks/1.0/applicationlinkForm/url/https://myhost.dk/jira/.json
The nginx proxy cleans up that url to the equivalent url https://myhost.dk/fecru/rest/applinks/1.0/applicationlinkForm/url/https:/myhost.dk/jira/.json which causes the exception.

When skipping the proxy it works fine.