Make labels for amend dialog better understandable

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

@@ -97,7 +97,7 @@
       </v-list-item>
       <v-card-actions>
         <edit-button
-          i18n-key="chronos.event.amend.title"
+          i18n-key="chronos.event.amend.button"
           @click="amendEvent.open = true"
         />
         <dialog-object-form

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

@@ -28,7 +28,8 @@
       "no_room": "No room",
       "current_changes": "Current changes",
       "amend": {
-        "title": "Amend",
+        "button": "Change",
+        "title": "Change lesson",
         "subject": "Subject",
         "teachers": "Teachers",
         "rooms": "Rooms",