Merge pull request #19646 from firlevapz/bugfix/19400/oauth2-login-opens-new-browser-window

Change OAuth2 redirect link to relative link

core/templates/loginflow/authpicker.php

 	<br/>
 
 	<p id="redirect-link">
-		<a href="<?php p($urlGenerator->linkToRouteAbsolute('core.ClientFlowLogin.grantPage', ['stateToken' => $_['stateToken'], 'clientIdentifier' => $_['clientIdentifier'], 'oauthState' => $_['oauthState']])) ?>">
+		<a href="<?php p($urlGenerator->linkToRoute('core.ClientFlowLogin.grantPage', ['stateToken' => $_['stateToken'], 'clientIdentifier' => $_['clientIdentifier'], 'oauthState' => $_['oauthState']])) ?>">
 			<input type="submit" class="login primary icon-confirm-white" value="<?php p($l->t('Log in')) ?>">
 		</a>
 	</p>