[api] only fetch bugzilla issues in issuetracking queue
[api] LDAP: Fixed incorrect usage of @login

'login' parameter was passed as a text to User.create in LDAP mode.
[api] Use be_not_nobody! in Package model check_source_access

If the source access is disabled for a package or project we want the user
to login. Therefore lets add a check for authentication before we raise the
exception so that clients that use anonymous requests have a chance to login.

Signed-off-by: Jan Blunck <jblunck@infradead.org>