Not showing previous query on clearing Codemirror and then clicking get saved query

[Piyush3079]

Steps to reproduce

1. In the current master clear the browser data of PMA and then logout.
2. Now Login again.
3. Go to sql tab of table, it will show select * from <table-name> where 1;
4. Now clear the code-mirror text and refresh again.
5. Click get auto saved query.

Expected behaviour

As we have cleared the code-mirror query and clicked get auto saved query, it will show previous saved query.

Actual behaviour

It is showing empty code-mirror while the hidden text-area is still showing the default query which either has to be with code-mirror too or will show previous query.

Client configuration

Browser:
Google Chrome

Operating system:
Linux 17.10