CollectionEdit: update mtime when editing and deleting collections.

src/Collections/CollectionEdit.tsx

@@ -91,7 +91,8 @@ export default function CollectionEdit(props: PropsType) {
     }
 
     const colMgr = getCollectionManager(etebase);
-    const meta = { ...info, color };
+    const mtime = (new Date()).getTime();
+    const meta = { ...info, color, mtime };
     let collection;
     if (props.collection) {
       collection = props.collection.collection;

src/Collections/Main.tsx

@@ -54,6 +54,9 @@ export default function CollectionsMain() {
 
   async function onDelete(collection: Etebase.Collection) {
     const colMgr = getCollectionManager(etebase);
+    const mtime = (new Date()).getTime();
+    const meta = await collection.getMeta();
+    await collection.setMeta({ ...meta, mtime });
     await collection.delete(true);
     await dispatch(collectionUpload(colMgr, collection));