LP#1648234 Apache redirects to standard ports

LP#1648234 Apache redirects to standard ports

Certain Apache redirects now send the browser to standard 80/443 ports
instead of defaulting to the internally configured Apache ports,
which may be non-standard, particularly in a proxied environment.

Leaking the non-standard ports to the browser causes the browser to
bypass the proxy and could cause the browser to request inaccessible
pages.

Paths affected by this patch:

/
/eg/staff
/opac/extras/slimpac/start.html
/opac/extras/slimpac/advanced.html
/opac/extras/slimpac/.*?locale=.*

To test:

1. Configure Apache to use non-standard ports for port 80/443 (e.g. 7080
and 7443).
2. Confirm the issue by navigatigating to http://HOST/
3. This should redirect to http://HOST:7080/eg/opac/home
4. Apply the Apache config changes and reload/restart Apache.
5. Clear the browser cache to reset any redirects
6. Navigate to http://HOST/
7. Confirm it redirects the browser to http://HOST/eg/opac/home

Signed-off-by: Bill Erickson <berickxx@gmail.com>
Signed-off-by: Ben Shum <ben@evergreener.net>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>