Remove unused translatable strings (#12643)

* Remove unused “salmon_url” string

* Remove more unused translatable strings

The following strings all used to be on the admin account page
but aren't used anymore: profile_url, outbox_url, followers_url, feed_url

config/locales/gl.yml

@@ -118,9 +118,7 @@ gl:
       email_status: Estado do correo
       enable: Habilitar
       enabled: Habilitado
-      feed_url: URL fonte
       followers: Seguidoras
-      followers_url: URL das seguidoras
       follows: Segue
       header: Cabeceira
       inbox_url: URL da Caixa de entrada
@@ -148,10 +146,8 @@ gl:
       no_account_selected: Non cambiou nada xa que non tiña nada seleccionado
       no_limits_imposed: Sen límites impostos
       not_subscribed: Non suscrita
-      outbox_url: URL caixa de saída
       pending: Pendente revisión
       perform_full_suspension: Suspender
-      profile_url: URL do perfil
       promote: Promocionar
       protocol: Protocolo
       public: Público
@@ -174,7 +170,6 @@ gl:
         moderator: Moderador
         staff: Membresía
         user: Usuaria
-      salmon_url: URL Salmon
       search: Busca
       search_same_ip: Outros usuarios co mesmo IP
       shared_inbox_url: URL da caixa de entrada compartida