Fix GitLabClient.js get wrong draw.io host path when window.location href contains "/"

[nic-6443]

relate to #493 (comment). For example, use
https://MyDraw.io/?gitlab=https://MyGitLab.com&gitlab-id=AppId to access my self host draw.io server, GitlabClient.js generate rediretUrl query parameter will be https://MyDraw.io/?gitlab=https://gitlab.html, correct should be https://MyDraw.io/gitlab.html.

[davidjgraph]

We can't merge this now since you've written your custom values to the diff.

If you want to set variable, use preConfig.js to write them without having to rebuild.

[nic-6443]

We can't merge this now since you've written your custom values to the diff.

If you want to set variable, use preConfig.js to write them without having to rebuild.

Sorry, the custom values setting was caused by my temporary test, I forgot it will be updated to this PR.
You can reconsider whether shoude accept the first commit for gitlab redirect url fix, if necessary I can reopen a new PR.

[davidjgraph]

What's an example URL where your first change fixes it?

[davidjgraph]

Ah sorry, you posted in top post, a lot of issues, reading too fast :).

[davidjgraph]

OK, the URL parameters must be URI encoded. If we're not decoded them, that's actually a different bug. Try again with properly encoded URL parameters

[nic-6443]

You are right, without URLencoding, href.lastIndexOf ('/')) may not find the correct route for current Draw.io.