bulk: increase limit on number of requests in container request

Motivation:
-----------

Recent of tape recalls revealed that FTS uses up to 2K request
per container whereas dCache default limit is 500. dCache returns
a 403 error in this case (subjetc of sepatate issue). But having
a better default would make admin life easier

Modification:
-------------

Raise bulk.limits.max.targets-per-flat-request to 500

Result:
-------

Do not need to adjust this value on all tape enabled WLCG sites
running dCache

Target: trunk
Request: 11.x 10.x 9.2

Require-book: no
Require-notes: yes

Author: DmitryLitvintsev

skel/share/defaults/bulk.properties

@@ -91,7 +91,7 @@ bulk.limits.max-requests-per-user=5000
 #  ---- The maximum number of unexpanded targets which can appear in the bulk request list.
 #       when request expansion is set to NONE.
 #
-bulk.limits.max.targets-per-flat-request=500
+bulk.limits.max.targets-per-flat-request=5000
 
 #  ---- The maximum number of unexpanded targets which can appear in the bulk request list.
 #       when request expansion is set to TARGETS.