Change "close_windows_when_empty" so that it includes dragging the final tab out of a window

At the moment setting "close_windows_when_empty" results in the following behaviour that I found unexpected, and request be changed.

Scenario:

Set "close_windows_when_empty" to true.

Open 2 files in a sublime window. Drag one tab to a new window.

Drag that one tab from the next window back to the original window

Expected behaviour:

The window now has no tabs or open folders, it should close.

Behaviour:

It doesn't close.