Follow Blog Widget: Strip Slashes on Subscribe Text (#39433)

Removes slashes from the Subscribe text output on the Follow Blog
widget. It looks like the Subscribe block already does this, which is
why the issue doesn't happen there. It's just been annoying me a bit
lately that the Follow Blog widget doesn't do the same too.

projects/plugins/jetpack/changelog/fix-subscribe-slashes

@@ -0,0 +1,4 @@
+Significance: patch
+Type: bugfix
+
+Subscriptions: fix added slashes to the Follow Blog widget.

projects/plugins/jetpack/modules/subscriptions/views.php

@@ -358,7 +358,7 @@ public static function render_widget_subscription_form( $args, $instance, $subsc
 		$show_subscribers_total       = (bool) $instance['show_subscribers_total'];
 		$subscribers_total            = self::fetch_subscriber_count();
 		$subscribe_text               = empty( $instance['show_only_email_and_button'] ) ?
-			wp_kses_post( $instance['subscribe_text'] ) :
+			wp_kses_post( stripslashes( $instance['subscribe_text'] ) ) :
 			false;
 		$referer                      = esc_url_raw( ( is_ssl() ? 'https' : 'http' ) . '://' . ( isset( $_SERVER['HTTP_HOST'] ) ? wp_unslash( $_SERVER['HTTP_HOST'] ) : '' ) . ( isset( $_SERVER['REQUEST_URI'] ) ? wp_unslash( $_SERVER['REQUEST_URI'] ) : '' ) );
 		$source                       = 'widget';