use DefaultScope.INSTANCE instead of deprecated constructor

plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/javascript/internal/core/JavaScriptCorePreferenceInitializer.java

diff --git a/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/javascript/internal/core/JavaScriptCorePreferenceInitializer.java b/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/javascript/internal/core/JavaScriptCorePreferenceInitializer.java
index 54e6d6a..672dbe7 100644
--- a/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/javascript/internal/core/JavaScriptCorePreferenceInitializer.java
+++ b/plugins/org.eclipse.dltk.javascript.core/src/org/eclipse/dltk/javascript/internal/core/JavaScriptCorePreferenceInitializer.java
@@ -11,7 +11,7 @@
 
 	@Override
 	public void initializeDefaultPreferences() {
-		final IEclipsePreferences preferences = new DefaultScope()
+		final IEclipsePreferences preferences = DefaultScope.INSTANCE
 				.getNode(JavaScriptPlugin.PLUGIN_ID);
 		TaskTagUtils.initializeDefaultValues(preferences);
 	}