Only link existing user if the setting is enabled

includes/openid-connect-generic-client-wrapper.php

@@ -416,6 +416,7 @@ class OpenID_Connect_Generic_Client_Wrapper {
 			if( $uid = email_exists( $email ) ) {
 				return $this->update_existing_user( $uid, $subject_identity );
 			}
+		}
 		
 		// allow other plugins / themes to determine authorization 
 		// of new accounts based on the returned user claim