gplugin/gplugin

Remove the gtk3 stuff from POTFILES that was missed previously

20 months ago, Gary Kramlich
36ab28b74138
Remove the gtk3 stuff from POTFILES that was missed previously

Testing Done:
ran `ninja gplugin-pot`

Reviewed at https://reviews.imfreedom.org/r/1779/
EionRobb <> EionRobb <eion@robbmob.com>
ivanhoe <107501-ivanhoe@users.noreply.gitlab.com> ivanhoe <ivanhoe@fiscari.de>
Richard Laager <rlaager@pidgin.im> <rlaager@wiktel.com>