Move adjustment of revision delete target in SpecialRevisiondelete to fix fatal

targetObj needs to be set correctly before accessing the RevisionList,
and trying to get the 'current'.  If not set correctly, then $title
given to RevisionList (and it's subclasses) is Special:Revisiondelete
and rev_page is 0. So nothing is found for 'current' and a fatal
error happens.

Follow-up to Id1baacb

Bug: 68566
Change-Id: Ic078af5417798db1b2900057dbf7514112e94b46

Conflicts:

	includes/specials/SpecialRevisiondelete.php
Merge branch 'REL1_23' of https://github.com/Vogone/mediawiki-core into REL1_23

Conflicts:
	includes/specials/SpecialRevisiondelete.php
Move adjustment of revision delete target in SpecialRevisiondelete to fix fatal

targetObj needs to be set correctly before accessing the RevisionList,
and trying to get the 'current'.  If not set correctly, then $title
given to RevisionList (and it's subclasses) is Special:Revisiondelete
and rev_page is 0. So nothing is found for 'current' and a fatal
error happens.