Improve home URL check.

https://secure.helpscout.net/conversation/2509177874/26892?viewId=1425710

src/HomeUrlController.php

@@ -36,7 +36,7 @@ public function init() {
 		$option = \get_option( 'pronamic_pay_home_url', null );
 
 		if ( null === $option ) {
-			\update_option( 'pronamic_pay_home_url', \home_url() );
+			\update_option( 'pronamic_pay_home_url', \get_option( 'home' ) );
 		}
 
 		\register_setting(
@@ -54,7 +54,7 @@ public function init() {
 				'type'              => 'string',
 				'description'       => \__( 'Home URL setting to detect changes in the WordPress home URL.', 'pronamic_ideal' ),
 				'sanitize_callback' => 'sanitize_url',
-				'default'           => \home_url(),
+				'default'           => \get_option( 'home' ),
 			]
 		);
 	}
@@ -74,7 +74,10 @@ public function admin_notices() {
 		 *
 		 * @link https://github.com/pronamic/wp-pay-core/issues/121
 		 */
-		if ( \get_option( 'home' ) === \get_option( 'pronamic_pay_home_url' ) ) {
+		$home_url_a = \get_option( 'home' );
+		$home_url_b = \get_option( 'pronamic_pay_home_url' );
+
+		if ( $home_url_a === $home_url_b ) {
 			return;
 		}
 
@@ -91,8 +94,8 @@ public function admin_notices() {
 					\sprintf(
 						/* translators: 1: Pronamic Pay home URL option, 2: home URL */
 						__( 'We noticed the WordPress home URL has changed from "%1$s" to "%2$s". Please verify the payment gateway settings. For example, you might want to switch between live and test mode or need to update an URL at the gateway to continue receiving payment status updates. Also keep an eye on pending payments to discover possible configuration issues.', 'pronamic_ideal' ),
-						\get_option( 'pronamic_pay_home_url' ),
-						\get_option( 'home' )
+						$home_url_b,
+						$home_url_a
 					)
 				);
 
@@ -148,7 +151,7 @@ public function admin_init() {
 			\wp_die( \esc_html__( 'You don’t have permission to do this.', 'pronamic_ideal' ) );
 		}
 
-		$result = \update_option( 'pronamic_pay_home_url', \home_url() );
+		$result = \update_option( 'pronamic_pay_home_url', \get_option( 'home' ) );
 
 		if ( false === $result ) {
 			\wp_die( \esc_html__( 'Action failed. Please refresh the page and retry.', 'pronamic_ideal' ) );