[mythtv] 2019-devel: Video editor cursor position not meaningful.

[John Pilkington]

This affects both my el7 and f30 builds of current head, c704391. It's 
new after the previous builds for both, at 0907c2db on 18 Nov.  I 
haven't tried master.

Theme is Myth-center-wide with minor tweaks.  The editor still works, 
and completed cuts are shown as red-on-green, but navigation using only 
the numerical display is 'difficult'; particularly so for radio :-)

Qt versions, if relevant, compile and run, are 5.9.7 for el7, 5.12.5 for 
f30.

Best regards,

John P