Bug 8896 QA Followup for regex

Bug 8896 QA Followup for regex

Making sure that the regex does not kill more than it should.
Amended: does now only look at separating colons(;) not commas(,).
Amended: two index expressions in direct context replaced by same regex for
consistency.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
(cherry picked from commit e5b467e81f494857a0831fe0d4f9ad94127a91bb)

Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>