fix(admin): DB Update notice appears on fresh install

[mathetos]

User Story

As a brand new Give user, I don't expect to be notified of the need to update my database on activation of the plugin for the first time. It should work out of the box immediately after activation.

Current Behavior

Currently, new Give users see the DB Update notice immediately after activating the plugin for the first time.

Expected Behavior

I expect that all new DB tables are created silently as soon as Give is activated for the first time.

Possible Solution

Create the new tables silently without a notification.

Steps to Reproduce

1. Create a fresh install
2. Install Give from "Plugins > Add New" (not Github)
3. Activate and confirm that the DB notice is there.

[kevinwhoffman]

@ravinderk I confirmed the DB notice is present on a fresh install of Give 2.1.5. Please let us know why this might be happening and move it to the top of your priority list so we can get a 2.1.6 patch out as soon as possible. Thanks.

[ravinderk]

Closing in favor of 7a17b22