Standartize on cancelled spelling with two l

aleksis/apps/chronos/frontend/components/calendar_feeds/details/LessonDetails.vue

@@ -155,8 +155,8 @@ export default {
             value: "room",
           },
           {
-            text: this.$t("chronos.event.amend.canceled"),
-            value: "canceled",
+            text: this.$t("chronos.event.amend.cancelled"),
+            value: "cancelled",
           },
           {
             text: this.$t("chronos.event.amend.comment"),

aleksis/apps/chronos/frontend/messages/en.json

@@ -30,7 +30,7 @@
         "subject": "Subject",
         "teacher": "Teacher",
         "room": "Room",
-        "canceled": "Cancel",
+        "cancelled": "Cancel",
         "comment": "Comment"
       }
     }

aleksis/apps/chronos/templates/chronos/partials/subs/room.html

 {% if type == "substitution" %}
   {% if el.cancelled or el.cancelled_for_teachers %}
-    {# Canceled lesson: no room #}
+    {# Cancelled lesson: no room #}
   {% elif el.room and el.lesson_period.room %}
     {# New and old room available #}
     <span class="tooltipped" data-position="bottom"