Bug 14144: Silence warnings t/db_dependent/Auth_with_ldap.t

Bug 14144: Silence warnings t/db_dependent/Auth_with_ldap.t

Revisiting this bug, I noticed that C4::Context->config() was mocked
poorly. I expanded the mock function a little and have quieted the
test which seemed to be working in a broken manner before.

TEST PLAN
---------
1) prove t/db_dependend/Auth_with_ldap.t
   -- shibboleth noise
2) apply this patch
3) prove t/db_dependend/Auth_with_ldap.t
   -- no noise
4) run koha qa test tools

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>