settings: Don't leak autoload plugins

Use the correct cleanup func

Part-of: <https://gitlab.gnome.org/GNOME/calls/-/merge_requests/756>

src/calls-settings.c

@@ -342,7 +342,7 @@ calls_settings_set_autoload_plugins (CallsSettings      *self,
       return;
   }
 
-  g_free (self->autoload_plugins);
+  g_strfreev (self->autoload_plugins);
   self->autoload_plugins = g_strdupv ((char **) plugins);
 
   if (!initial)