Qt: don't use monospace fonts for licence dialog.
Authors and licence dialogs were using monospace fonts to resemble
GTK interface. Authors is not monospace anymore. Not using monospace
for license dialog makes the text look more similar to other dialogs
and more readable.
Change-Id: I5a62f0993d579af5b1db7dea351d9a10175a069d
Reviewed-on: https://code.wireshark.org/review/35663
Petri-Dish: Dario Lombardo <lomato@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Reviewed-by: Gerald Combs <gerald@wireshark.org>