pidgin/pidgin

Drop PidginCredentialProviderStore.

2021-05-13, Elliott Sales de Andrade
17208bd7a906
Drop PidginCredentialProviderStore.

It's no longer needed now that the prefs use a `GtkListBox`.

Testing Done:
Compile only.

Reviewed at https://reviews.imfreedom.org/r/650/
i18n = import('i18n')
i18n.gettext('pidgin',
args : '--from-code=utf-8',
install : get_option('nls'),
)