Create missing parent folders as unselectable

app/src/main/java/eu/faircode/email/Core.java

@@ -1308,6 +1308,20 @@ class Core {
         Log.i("Updating folder parents=" + parentFolders.size());
         for (String parentName : parentFolders.keySet()) {
             EntityFolder parent = nameFolder.get(parentName);
+            if (parent == null && parentName != null) {
+                parent = new EntityFolder();
+                parent.account = account.id;
+                parent.name = parentName;
+                parent.type = EntityFolder.SYSTEM;
+                parent.synchronize = false;
+                parent.subscribed = false;
+                parent.poll = false;
+                parent.sync_days = 0;
+                parent.keep_days = 0;
+                parent.selectable = false;
+                parent.id = db.folder().insertFolder(parent);
+                nameFolder.put(parentName, parent);
+            }
             for (EntityFolder child : parentFolders.get(parentName))
                 db.folder().setFolderParent(child.id, parent == null ? null : parent.id);
         }