Help/About: Clarify a string about lazy-loading iframes.

Props davidbaumwald, audrasjb, hellofromTonya.
See #52347.
Built from https://develop.svn.wordpress.org/branches/5.7@50492


git-svn-id: http://core.svn.wordpress.org/branches/5.7@50105 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/about.php

@@ -207,7 +207,7 @@ require_once ABSPATH . 'wp-admin/admin-header.php';
 				<p><?php _e( 'For years jQuery helped make things move on the screen in ways the basic tools couldn’t—but that keeps changing, and so does jQuery.' ); ?></p>
 				<p><?php _e( 'In 5.7, jQuery gets more focused and less intrusive, with fewer messages in the console.' ); ?></p>
 				<h3><?php _e( 'Lazy-load your iframes' ); ?></h3>
-				<p><?php _e( 'Now it’s simple to let iframes lazy-load. Just add the <code>loading="lazy"</code> attribute to iframe tags on the front end.' ); ?></p>
+				<p><?php _e( 'Now it’s simple to let iframes lazy-load. By default, WordPress will add a <code>loading="lazy"</code> attribute to iframe tags when both width and height are specified.' ); ?></p>
 			</div>
 		</div>
 

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-RC2-50489';
+$wp_version = '5.7-RC2-50492';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.