keep focus on current element when updating gallery

            let galleryBtnSelected = gradioApp().querySelector('#'+id_gallery+' .gallery-item.\\!ring-2')

            if (prevSelectedIndex !== -1 && galleryButtons.length>prevSelectedIndex && !galleryBtnSelected) {

                //automatically re-open previously selected index (if exists)

                activeElement = document.activeElement;

                galleryButtons[prevSelectedIndex].click();

                showGalleryImage();

                if(activeElement) activeElement.focus()

            }

        })

        galleryObservers[id_gallery].observe( gallery, { childList:true, subtree:false })