fix migration for DBs which did not have _hidden tree created, closes #3536

db/migrations/0200__create_hidden_subtree.js

@@ -7,6 +7,6 @@ module.exports = () => {
         beccaLoader.load();
         // make sure the hidden subtree exists since the subsequent migrations we will move some existing notes into it (share...)
         // in previous releases hidden subtree was created lazily
-        hiddenSubtreeService.checkHiddenSubtree();
+        hiddenSubtreeService.checkHiddenSubtree(true);
     });
 };

src/services/hidden_subtree.js

@@ -234,8 +234,8 @@ const HIDDEN_SUBTREE_DEFINITION = {
     ]
 };
 
-function checkHiddenSubtree() {
-    if (!migrationService.isDbUpToDate()) {
+function checkHiddenSubtree(force = false) {
+    if (!force && !migrationService.isDbUpToDate()) {
         // on-delete hook might get triggered during some future migration and cause havoc
         log.info("Will not check hidden subtree until migration is finished.");
         return;