Use explicit background-size 50px 50px instead of 'cover'

The 'cover' keyword was producing fallback 'auto auto' rendering in some
environments (likely a kses/CSS shorthand quirk). Switching to explicit
pixel values matching the container size has the same visual effect
for the 270x270 source image and works reliably across all browsers.

templates/single-projects.php

@@ -142,7 +142,7 @@ if ( $last_updated ) {
 
             <?php if ( $settings['templates']['github_owner'] && $owner_avatar && $owner_name ) : ?>
                 <div class="project-owner">
-                    <span class="project-owner-avatar" style="display:block !important;width:50px !important;height:50px !important;min-width:50px !important;min-height:50px !important;max-width:50px !important;max-height:50px !important;border-radius:50% !important;background-image:url('<?php echo esc_url( $owner_avatar ); ?>') !important;background-size:cover !important;background-position:center center !important;background-repeat:no-repeat !important;flex-shrink:0 !important;flex-grow:0 !important;" aria-label="<?php echo esc_attr( $owner_name ); ?>" role="img"></span>
+                    <span class="project-owner-avatar" style="display:block !important;width:50px !important;height:50px !important;min-width:50px !important;min-height:50px !important;max-width:50px !important;max-height:50px !important;border-radius:50% !important;background-image:url('<?php echo esc_url( $owner_avatar ); ?>') !important;background-size:50px 50px !important;background-position:center center !important;background-repeat:no-repeat !important;flex-shrink:0 !important;flex-grow:0 !important;" aria-label="<?php echo esc_attr( $owner_name ); ?>" role="img"></span>
                     <span class="project-owner-name">
                         <a href="<?php echo esc_url( $owner_url ); ?>" target="_blank" rel="noopener noreferrer"><?php echo esc_html( $owner_name ); ?></a>
                     </span>