feat: allow registering via oauth when main is disabled

Author: RyanTheAllmighty

conf/default.php

@@ -8,3 +8,4 @@
 $conf['client-key'] = '';
 $conf['client-secret'] = '';
 $conf['redirect-uri'] = '';
+$conf['register-on-auth'] = 0;

conf/metadata.php

@@ -29,3 +29,4 @@ public function html(&$plugin, $echo = false) {
 $meta['client-key'] = array('string');
 $meta['client-secret'] = array('string');
 $meta['redirect-uri'] = array('string');
+$meta['register-on-auth'] = array('onoff','_caution' => 'security');

lang/en/settings.php

@@ -9,3 +9,4 @@
 $lang['info'] = 'Redirect URI to use when configuring the applications';
 $lang['client-key'] = 'The Client ID';
 $lang['client-secret'] = 'The Client Secret';
+$lang['register-on-auth'] = 'Register authenticated users even if self-registration is disabled in main configuration';