I am having the same problem after my update failed I restored the host files and the db. The outward-facing site still shows " We'll be back soon. We are currently updating our shop and will be back really soon. Thanks for your patience.". When I log in as admin I get no errors but I go to the same display.
I can then login as admin but it takes me to the site maintenance page.
How do I get the site out of maintenance mode?