Do not require X11 DISPLAY for CLI prefs changes

Settings preferences does not need a splash-screen. Avoid needing an X11 DISPLAY in this case so CI solutions do not bail out (e.g. Travis).
More information in arduino#5131.

This fixes arduino#5131.

Author: dagwieers

Diff for: build/linux/dist/arduino

@@ -27,7 +27,7 @@ fi
 # Collect options to java in an array, to properly handle whitespace in options
 JAVA_OPTIONS=("-DAPP_DIR=$APPDIR" "-Dswing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel")
 
-if [[ "$@" != *"--upload"* && "$@" != *"--verify"* && "$@" != *"--get-pref"* && "$@" != *"--install-board"* && "$@" != *"--install-library"* ]] ; then
+if [[ "$@" != *"--upload"* && "$@" != *"--verify"* && "$@" != *"--get-pref"* && "$@" != *"--pref"* && "$@" != *"--install-board"* && "$@" != *"--install-library"* ]] ; then
 	JAVA_OPTIONS+=("-splash:$APPDIR/lib/splash.png")
 fi