message: [Build] Use Qt5 by default instead of Qt4
  Qt4 is mostly depreciated now, and all of our testing/release builds
  are done using Qt5, so it makes sense to use Qt5 as the default search
  version.
diff: @@ -542,7 +542,7 @@ fi
  BITCOIN_QT_INIT
  dnl sets $bitcoin_enable_qt, $bitcoin_enable_qt_test, $bitcoin_enable_qt_dbus
  -BITCOIN_QT_CONFIGURE([$use_pkgconfig], [qt4])
  +BITCOIN_QT_CONFIGURE([$use_pkgconfig], [qt5])
  if test x$build_bitcoin_utils$build_bitcoind$bitcoin_enable_qt$use_tests = xnononono; then
  use_boost=no
  