gplugin/gplugin

gi-docgen now errors if your annotations are wrong, so this fixes ours

Testing Done:
Ran the build with docs enabled until it succeeded.

Reviewed at https://reviews.imfreedom.org/r/1131/
if get_option('nls')
i18n.gettext(GETTEXT_PACKAGE)
else
summary('translations',
'You have disabled installation of translations which means ' +
'English will be the only available language.',
section : 'Warnings')
endif