Don't always $cookie_path, only set it when needed

lib/base.php

@@ -741,13 +741,12 @@ class OC {
 					OC_Preferences::deleteKey(OC_User::getUser(), 'login_token', $_COOKIE['oc_token']);
 				}
 				if (isset($_SERVER['PHP_AUTH_USER'])) {
-					$cookie_path = OC::$WEBROOT ? : '/';
 					if (isset($_COOKIE['oc_ignore_php_auth_user'])) {
 						// Ignore HTTP Authentication for 5 more mintues.
-						setcookie('oc_ignore_php_auth_user', $_SERVER['PHP_AUTH_USER'], time() + 300, $cookie_path);
+						setcookie('oc_ignore_php_auth_user', $_SERVER['PHP_AUTH_USER'], time() + 300, OC::$WEBROOT.(empty(OC::$WEBROOT) ? '/' : ''));
 					} elseif ($_SERVER['PHP_AUTH_USER'] === self::$session->get('loginname')) {
 						// Ignore HTTP Aunthentication to allow a different user to log in.
-						setcookie('oc_ignore_php_auth_user', $_SERVER['PHP_AUTH_USER'], 0, $cookie_path);
+						setcookie('oc_ignore_php_auth_user', $_SERVER['PHP_AUTH_USER'], 0, OC::$WEBROOT.(empty(OC::$WEBROOT) ? '/' : ''));
 					}
 				}
 				OC_User::logout();