CommandLineTest: Produce less verbose output

In one test, `--get-pref` is passed on the commandline to prevent
starting the full GUI. When ran without arguments, `--get-pref` causes
*all* preferences to be printed. Using `--version` achieves the same (no
GUI is started) with just a single line of output.

app/test/processing/app/CommandLineTest.java

@@ -111,7 +111,7 @@ public class CommandLineTest {
     runArduino(true, true, null, new String[] {
         "--save-prefs",
         "--preferences-file", prefFile.getAbsolutePath(),
-        "--get-pref", // avoids starting the GUI
+        "--version", // avoids starting the GUI
     });
 
     runArduino(true, true, null, new String[] {