preserve query string during session Initiator

[Peter Schober]

* Jehan Procaccia <Jehan.Procaccia at it-sudparis.eu> [2015-03-12 10:55]:
> <p>If you have a shibboleth account,
> please<a  href="https://site.domain.fr/Shibboleth.sso/Login?target=https://server.domain.fr/cgi-bin/koha/opac-reserve.pl  <view-source:https://mediatheques.mines-telecom.fr/Shibboleth.sso/Login?target=https://mediatheques.mines-telecom.fr/cgi-bin/koha/opac-reserve.pl>">click here to login</a>.</p>

The page/code that /generates/ the above HTML needs to be fixed
(changed) to include the current REQUEST_URI the subject is viewing.

Once you're at /cgi-bin/koha/opac-reserve.pl without the query string
it's guesswork (as the user agent may or may not provide you with a
'referer' header with the correct value).
-peter