info-provider: Fix regression in publishing GlueServiceEndpoint

Target: trunk
Request: 2.7
Require-notes: yes
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6246/
(cherry picked from commit fb55fb8498c16a7353d1e3a6169d5ac31058ca7f)
Merge pull request #298 from gbehrmann/fix/2.7/rb6246

info-provider: Fix regression in publishing GlueServiceEndpoint