Customizer: Only show the default button in the upload control if there is a default attachment.

props celloexpressions.
see #21483.
Built from https://develop.svn.wordpress.org/trunk@30553


git-svn-id: http://core.svn.wordpress.org/trunk@30542 1a063a9b-81f0-0310-95a4-ce76da25c4cd

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

@@ -795,7 +795,7 @@ class WP_Customize_Upload_Control extends WP_Customize_Control {
 		<# } else { #>
 			<p class="placeholder-text"><?php echo $this->button_labels['placeholder']; ?></p>
 			<a class="button upload-button" id="{{ data.settings.default }}-button" href="#"><?php echo $this->button_labels['select']; ?></a>
-			<# if ( ! data.defaultAttachment ) { #>
+			<# if ( data.defaultAttachment ) { #>
 				<a class="default-button remove-button" href="#"><?php echo $this->button_labels['default']; ?></a>
 			<# } #>
 		<# } #>

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.1-beta2-30552';
+$wp_version = '4.1-beta2-30553';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.