Fix a typo in public.js (double semicolons) (#4269)

Signed-off-by: Cygnan <mail@cygnan.com>

app/javascript/packs/public.js

@@ -35,7 +35,7 @@ function main() {
 
     [].forEach.call(document.querySelectorAll('time.time-ago'), (content) => {
       const datetime = new Date(content.getAttribute('datetime'));
-      content.textContent = relativeFormat.format(datetime);;
+      content.textContent = relativeFormat.format(datetime);
     });
   });