pool: Fix ISE in 'rep ls'

Target: trunk
Request: 2.10
Request: 2.9
Request: 2.8
Request: 2.7
Request: 2.6
Require-notes: yes
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: https://rb.dcache.org/r/7369/
(cherry picked from commit f743599fc7cc72d7a3b88fda030d088df2096bd0)

Conflicts:
	modules/dcache/src/main/java/org/dcache/pool/repository/RepositoryInterpreter.java
Merge pull request #939 from gbehrmann/fix/2.8/rb7369

pool: Fix ISE in 'rep ls'