[Serusers] Via header inserted with public IP

[Gaurav Kulshreshtha]

All.
 I m using SER 0.9.7pre1 with RTPProxy and this box sits on the boundary
of private and public networks. REGISTERs hit this box from public side
and are forwarded to private side for registration processing.
The message is forwarded to the private ip but there are two weird
things I noticed ..
a) Even though the packet leaves from the private interface the src ip
address is set to public IP
b) Newly added Via header has public side IP address and not the private
side IP address. This causes problems in routing the response to
REGISTER method.

Any suggestions welcomes

Thanks
Gaurav Kulshreshtha