Fix the text domain on the settings sidebar heading

`views/part-rocket-ad.php:26` passed 'corporate' as the text domain instead of
'imagify', so "We recommend for you" never matched a translation and always
rendered in English regardless of locale.

Unrelated to the banner copy in #1044 - different file, different placement -
but found while tracing which WP Rocket banner the ticket meant, and it is a
one-word fix in the same area.

Author: Miraeld

views/part-rocket-ad.php

@@ -23,7 +23,7 @@
 <div class="imagify-col imagify-sidebar">
 	<div class="imagify-sidebar-section">
 		<p class="imagify-sidebar-title">
-			<?php esc_html_e( 'We recommend for you', 'corporate' ); ?>
+			<?php esc_html_e( 'We recommend for you', 'imagify' ); ?>
 		</p>
 
 		<img src="<?php echo esc_url( IMAGIFY_ASSETS_IMG_URL ); ?>logo-wprocket.png" srcset="<?php echo esc_url( IMAGIFY_ASSETS_IMG_URL ); ?>logo-wprocket.svg 1x, <?php echo esc_url( IMAGIFY_ASSETS_IMG_URL ); ?>logo-wprocket.svg 2x" alt="WP Rocket" width="232" height="63">