Revert "[not verified] SSO: Validate the wpcom_user_id"

This reverts commit e98c3ba.

This commit seemed to cause issues in some SSO environments.

Author: jeherve

modules/sso.php

@@ -700,15 +700,6 @@ function handle_login() {
 			$user_found_with = 'external_user_id';
 			$user = get_user_by( 'id', intval( $user_data->external_user_id ) );
 			if ( $user ) {
-				$expected_id = get_user_meta( $user->ID, 'wpcom_user_id', true );
-				if ( $expected_id && $expected_id !== $user_data->ID ) {
-					$error = new WP_Error( 'expected_wpcom_user', __( 'Something got a little mixed up and an unexpected WordPress.com user logged in.', 'jetpack' ) );
-
-					/** This filter is documented in core/src/wp-includes/pluggable.php */
-					do_action( 'wp_login_failed', $user_data->login, $error );
-					add_filter( 'login_message', array( 'Jetpack_SSO_Notices', 'error_invalid_response_data' ) ); // @todo Need to have a better notice. This is only for the sake of testing the validation.
-					return;
-				}
 				update_user_meta( $user->ID, 'wpcom_user_id', $user_data->ID );
 			}
 		}