multimedia/smtube: Build with qt5 by default

multimedia/smtube/README

@@ -2,9 +2,3 @@ SMTube is an application that allows to browse, search and play YouTube
 videos. Videos are played back with a media player (by default SMPlayer)
 instead of a flash player, this allows better performance, particularly
 with HD content.
-
-If you prefer to build SMTube against Qt5 rather than Qt4, install qt5
-and qt5-webkit (both available from SlackBuilds.org) and run the script
-like that:
-
-  USE_QT5=yes ./smplayer.SlackBuild

multimedia/smtube/smtube.SlackBuild

@@ -70,7 +70,7 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
   -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
-if [ ${USE_QT5:-no} = yes ]; then
+if [ ${USE_QT5:-yes} = yes ]; then
   QMAKE=qmake-qt5
   LRELEASE=lrelease-qt5
 else