[Vortex] Bug-fix: Reply frame sometimes missing channel_ref

[Jens Alfke]

My application receives a largish reply (~32k), calls  
vortex_frame_get_channel_ref to find the channel, and unexpectedly  
gets back NULL. It then dies when it tries to access that channel.

I tracked down the source of the problem:  
vortex_channel_build_single_pending_frame( ) creates a new  
VortexFrame, but does not assign itself as the channel_ref. The fix is  
simple: after the call to vortex_frame_create_full_ref, add the line
	vortex_frame_set_channel_ref(result, channel);
That's on line 1729 of vortex_channel.c, in my sources.

Apologies for not attaching a patch file, but I still haven't had the  
chance to update my Vortex sources lately. At least this is just a one- 
liner, so it should be easy to paste in the fix.

--Jens