Fix following_counter plural to include "one" (#14342)

Fix following_counter plural to include "one" (#14342)

That should've worked just fine, but unfortunately, Crowdin wasn't able
to pick up on our non-existent "one" category, thus appending empty
translation block to people's translations. Empty block WILL BE used by
any ICU FormatMessage library, thus resulting in an empty translation
for "one" category, and that requires immediate fix.

This commit duplicates contents of the "other" plural category.