(Bug 41436) Tone down sanity check, just warn, don't die.

(Bug 41436) Tone down sanity check, just warn, don't die.

This is a follow-up to I9db228c3 fixing an issue with undelete:

Page ID 47009 mismatches the ID 47010 provided by the Title object.

Backtrace:

0 /var/www/CephWiki/core/includes/Revision.php(188): Revision->__construct(Array)
1 /var/www/CephWiki/core/includes/specials/SpecialUndelete.php(548): Revision::newFromArchiveRow(Object(stdClass), Array)
2 /var/www/CephWiki/core/includes/specials/SpecialUndelete.php(381): PageArchive->undeleteRevisions(Array, false, '')
3 /var/www/CephWiki/core/includes/specials/SpecialUndelete.php(1510): PageArchive->undelete(Array, '', Array, false, Object(User))
4 /var/www/CephWiki/core/includes/specials/SpecialUndelete.php(778): SpecialUndelete->undelete()
5 /var/www/CephWiki/core/includes/SpecialPage.php(599): SpecialUndelete->execute(NULL)

Change-Id: I0517c5826bcba2a85fee596b0473a16da26c3b2f