Make the ScriptService normal priority

It was made high priority years ago in order to cause its scripts
to be registered before the MenuService built the menu; see
imagej/ImageJ@34be53a.

But it does not seem necessary anymore.

Author: ctrueden

src/main/java/org/scijava/script/DefaultScriptService.java

@@ -75,7 +75,7 @@
  * @author Johannes Schindelin
  * @author Curtis Rueden
  */
-@Plugin(type = Service.class, priority = Priority.HIGH)
+@Plugin(type = Service.class)
 public class DefaultScriptService extends
 	AbstractSingletonService<ScriptLanguage> implements ScriptService
 {

src/test/java/org/scijava/ContextCreationTest.java

@@ -87,7 +87,6 @@ public void testNoPlugins() {
 	public void testFull() {
 		final Class<?>[] expected =
 			{ org.scijava.event.DefaultEventService.class,
-				org.scijava.script.DefaultScriptService.class,
 				org.scijava.app.DefaultAppService.class,
 				org.scijava.app.DefaultStatusService.class,
 				org.scijava.command.DefaultCommandService.class,
@@ -113,6 +112,7 @@ public void testFull() {
 				org.scijava.prefs.DefaultPrefService.class,
 				org.scijava.run.DefaultRunService.class,
 				org.scijava.script.DefaultScriptHeaderService.class,
+				org.scijava.script.DefaultScriptService.class,
 				org.scijava.script.process.DefaultScriptProcessorService.class,
 				org.scijava.startup.DefaultStartupService.class,
 				org.scijava.task.DefaultTaskService.class,