fix: only update image if textbox populated

index.html

@@ -106,9 +106,11 @@
     }
 
     document.getElementById('tweetURL').addEventListener('change', function(e) {
+      if (e.target.value.trim() != "") {
         let parts = e.target.value.split("/");
         let tweetID = parts[parts.length-1];
         loadTweet(tweetID);
+      }
     });
 
     document.getElementById('imageTagExample').addEventListener('click', function(e) {