Gnucash 2.6.15 loss of window focus on Mac.

[David Bergum]

In Gnucash 2.6.15 when using a secondary window, like the options window for a report, I get one click in that window before focus is lost and any click on that window is applied to the underlying window.  The title bar grays out.  In order to regain focus I have to click on the title bar, and then I"ll get one click in the window before focus is lost again.  I'm running macOS Sierra, 10.12.3.

Dave