Bug 878700 - Untranslated text in 'Enter PIN' screen

Simple s/data-l10-id/data-l10n-id change as suggested by
Staś Małolepszy at in comment 6 of bug 878700.
Merge pull request #12344 from overholt/master

Bug 878700 - Untranslated text in 'Enter PIN' screen r=fcampo