Elements in rtpbin don't set PROXY_ALLOCATION flag

Submitted by Jason Litzinger

Link to original bug (#723850)

Description

The PROXY_ALLOCATION flag is not currently set in any of the elements in the rtpbin (e.g. rtpsession, jitterbuffer, etc.). The effect is that allocation queries sent by the source during 'reconfigure' (i.e. after linking) never make it to the downstream sink.

Version: 1.2.2