Two strings used in the Presentation Optimizer were using a count
without using pluralisable strings. They are only used with counts > 1
so maybe the assumption was that there is only one possible plural form,
but of course some languages have several plural forms that need
differing strings even for larger numbers.
I noticed this because the French translation was incorrect for
STR_DELETE_SLIDES as if %SLIDES was going to be replaced by a type of
slide rather than a number. Maybe if the string had plural forms that
would have been more obvious.
Change-Id: Icf2df1bfed3907226e45e819ad0c14c4a33e8bfe
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/206314
Tested-by: Jenkins
Reviewed-by: Neil Roberts <nroberts@libreoffice.org>