QmlOutline: Increase delay before doing an update to 500ms

Use same delay as in cppeditor. Hopefully prevents the Outline to be
updated while typing.

src/plugins/qmljseditor/qmljseditor.cpp

@@ -78,7 +78,7 @@
 enum {
     UPDATE_DOCUMENT_DEFAULT_INTERVAL = 50,
     UPDATE_USES_DEFAULT_INTERVAL = 150,
-    UPDATE_OUTLINE_INTERVAL = 150 // msecs after new semantic info has been arrived / cursor has moved
+    UPDATE_OUTLINE_INTERVAL = 500 // msecs after new semantic info has been arrived / cursor has moved
 };
 
 using namespace QmlJS;