audio/ngjackspa: Enabled gtkmm interface by default

Signed-off-by: Robby Workman <rworkman@slackbuilds.org>

audio/ngjackspa/README

@@ -5,9 +5,8 @@ providing JACK ports for its audio inputs and outputs, and dynamic setting
 of its control inputs. Additionally, the plugin controls can be exported
 to or controlled by control voltages on standard JACK audio ports.
 
-By default, the Qt user interface is built, and the gtkmm UI is disabled.
-To disable Qt, set QT=no in the script's environment. To enable gtkmm,
-set GTKMM=yes (this will require gtkmm to be installed, of course).
+By default, both the Qt and gtkmm user interfaces are built.  To disable 
+one or both of them, set QT=no and/or GTKMM=no in the script's environment.
 
 This package uses POSIX filesystem capabilities to execute with
 elevated privileges (required for realtime audio processing). This

audio/ngjackspa/ngjackspa.SlackBuild

@@ -54,7 +54,7 @@ find -L . \
  -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
 # build options
-GTKMM="${GTKMM:-no}"
+GTKMM="${GTKMM:-yes}"
 QT="${QT:-yes}"
 
 # dike out the parts the user disabled