Simplifying context

Co-authored-by: Aaron Jorbin <aaronjorbin@users.noreply.github.com>

Author: t-hamano

src/wp-admin/customize.php

@@ -210,7 +210,7 @@
 			<span class="spinner"></span>
 			<button type="button" class="customize-controls-preview-toggle">
 				<span class="controls"><?php _e( 'Customize' ); ?></span>
-				<span class="preview"><?php echo esc_html_x( 'Preview', 'noun, customizer toggle label for the preview pane' ); ?></span>
+				<span class="preview"><?php echo esc_html_x( 'Preview', 'noun' ); ?></span>
 			</button>
 			<a class="customize-controls-close" href="<?php echo esc_url( $wp_customize->get_return_url() ); ?>">
 				<span class="screen-reader-text">