ugoiras: don't initialize notes on ugoiras.

Fixes note font scaling increasing the size of the ugoira playback controls.

app/javascript/src/javascripts/notes.js

@@ -883,7 +883,7 @@ class Note {
   }
 
   static initialize_all() {
-    if ($("#c-posts #a-show #image").length === 0 || $("video#image").length) {
+    if ($("#c-posts #a-show #image").length === 0 || $("video#image").length || $("canvas#image").length) {
       return;
     }