prevent highlighting/selecting image

javascript/imageviewer.js

@@ -116,6 +116,7 @@ function showGalleryImage() {
                 e.dataset.modded = true;
                 if(e && e.parentElement.tagName == 'DIV'){
                     e.style.cursor='pointer'
+                    e.style.userSelect='none'
                     e.addEventListener('click', function (evt) {
                         if(!opts.js_modal_lightbox) return;
                         modalZoomSet(gradioApp().getElementById('modalImage'), opts.js_modal_lightbox_initially_zoomed)