[ixpmanager] Bug in rendering of the Router screen

[Mark Prior]

I've been playing with IXP manager on my Debian system (so I've had to
take the manual installation path) and I've noticed some strange
behaviour with the Routers screen. I use Let's Encrypt certificates on
my web sites and so the apache confguration for the web site I've
created for this ixp manager instance has a redirect on port 80 to the
https version.

Initially I was lazy and hadn't changed the default setting for APP_URL
in the .env file and while the other screens worked fine (I could create
Customers, Infrastructures, Switches, etc) the Router screen gave the
appearance of missing the CSS. Note I don't have a web service listening
on port 8088 (which is the default value for APP_URL).

I edited the .env file to include the URL for the web site but neglected
to change http to https and got the same result, ie missing CSS. Note
that there is a redirect in the apache configuration so when you try to
display /router/list there is a 302 redirect to the https site (although
the initial login redirects you to the https site if there wasn't an
absolute URL being used later).

I eventually worked out that I was missing the "s" and changed APP_URL
appropriately and now I get the raft of CSS and JS files loaded so that
the Routers screen renders properly.

What's curious (and the bug) is the lack of CSS when APP_URL points to a
site that has a redirect.

Mark.