srm: Fix restore of bring-online requests on restart

A regression introduced in 2.10.0 prevents the SRM from starting
when active bring-online requests are found in the SRM database.
The problem is that the scheduler timestamp isn't updated when
restoring jobs. This patch resolves the issue.

Target: trunk
Request: 2.10
Require-notes: yes
Require-book: no
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: https://rb.dcache.org/r/7224/
(cherry picked from commit b3e9b74570779f3a94f464c74984208b2b59512e)