x11/qtermwidget: update to 0.16.1

0.16.1
-Bumped version to 0.16.1, for a point release of qterminal.

0.16.0
-Use qAsConst.
-Don't search application dir for keyboard and scheme data.
-Use Q_EMIT to call signals, instead of the emit keyword.
-Dropped the deprecated class QLinkedList.
-Don't use 0/nullptr to initialize QFlags.
-Fixed ColorEntry copy operator.
-Disabled the use of copy constructors and assignment operators.
-Check for successful ioctl() calls by testing that the call did not return -1.
-Fix find_package() developer warning in cmake.
-Use const references wherever possible.
-Handle keyboard commands properly.

(pin)