Bug 5683 follow-up: calls to ModBiblio can still fail

Bug 5683 follow-up: calls to ModBiblio can still fail

Because C4::Charset directly manipulates the MARC::Record object, bad data has
to be cleaned in ModBiblio before the call into C4::Charset. The corrupted
records can also break the Zebra index. After this fix has been applied, it
would probably be a good idea to run the misc/maintenance/touch_all_biblios.pl
script to ensure that this problem has been cleared up.

Signed-off-by: Jared Camins-Esakov <jcamins@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>