switch ( $column_name ) {
case 'cb': ?>
<th scope="row" class="check-column">
+ <?php if ( ! is_main_site( $blog['blog_id'] ) ) : ?>
<label class="screen-reader-text" for="blog_<?php echo $blog['blog_id']; ?>"><?php printf( __( 'Select %s' ), $blogname ); ?></label>
<input type="checkbox" id="blog_<?php echo $blog['blog_id'] ?>" name="allblogs[]" value="<?php echo esc_attr( $blog['blog_id'] ) ?>" />
+ <?php endif; ?>
</th>
<?php
break;