Customize: Change attachment condition in the site icon control to prevent errors.

Props neverything.
Fixes #36749 for trunk.
Built from https://develop.svn.wordpress.org/trunk@37456


git-svn-id: http://core.svn.wordpress.org/trunk@37424 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/customize/class-wp-customize-site-icon-control.php

@@ -59,7 +59,7 @@ class WP_Customize_Site_Icon_Control extends WP_Customize_Cropped_Image_Control
 			<# } #>
 		</label>
 
-		<# if ( data.attachment && data.attachment.id ) { #>
+		<# if ( data.attachment && data.attachment.id && data.attachment.sizes ) { #>
 			<div class="attachment-media-view">
 				<div class="site-icon-preview">
 					<div class="favicon-preview">

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-alpha-37452';
+$wp_version = '4.6-alpha-37456';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.