Do not thread by default, but let the user choose.

Issue-ID: RIC-228
Change-Id: Iab4acea6b235cdf5acf734b23b0aa735ee41e19c
Signed-off-by: Tommy Carpenter <tc677g@att.com>
diff --git a/examples/pong_xapp.py b/examples/pong_xapp.py
index b19beec..ac72813 100644
--- a/examples/pong_xapp.py
+++ b/examples/pong_xapp.py
@@ -44,4 +44,4 @@
 
 xapp = RMRXapp(default_handler=defh, post_init=post_init, use_fake_sdl=True)
 xapp.register_callback(sixtyh, 60000)
-xapp.run()
+xapp.run()  # will not thread by default