allow svg in acf image field

svg_acf_image.php

<?php $image = get_sub_field('features_img');

                            if( !empty($image) ): 

                                // vars
                                $url = $image['url'];
                                $title = $image['title'];
                                $alt = $image['alt'];
                                $caption = $image['caption'];

                                // thumbnail
                                $size = 'bigImg';
                                $thumb = $image['sizes'][ $size ];
                                $width = $image['sizes'][ $size . '-width' ];
                                $height = $image['sizes'][ $size . '-height' ];

                                $svgfile = simplexml_load_file($url);
                                $width_svg = substr($svgfile[width],0,-2);
                                $height_svg = substr($svgfile[height],0,-2);

                                ?>

                                  <div class="imgCont">
                                      <img src="<?php echo $thumb; ?>" alt="<?php echo $alt; ?>" width="<?php echo $width_svg; ?>" height="<?php echo $height_svg; ?>" />
                                  </div>      


                            <?php endif; ?>