chimera: Add messages to JdbcFs#move exceptions

Otherwise the exceptions will have a null message, which in other
places may lead to rather meaningless error messages being logged.

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/7403/
(cherry picked from commit 65d750447f276b0a45c163edd406e244c41fd49c)

Conflicts:
	modules/chimera/src/main/java/org/dcache/chimera/JdbcFs.java

(cherry picked from commit 17b6c995dc09266680f007126de428ba2f35ce3a)
Merge pull request #996 from gbehrmann/fix/2.6/rb7403

chimera: Add messages to JdbcFs#move exceptions