Bug#764576: linphone-nogtk: Blind Transfer fails with SIP 429

[Florian Bach]

Package: linphone-nogtk
Version: 3.5.2-10
Severity: normal

Dear Maintainer,

I have linphonec installed on my Ubuntu 14.04, and I have a SIP account 
registered from my AVM FRITZ!Box 6360. 

When I now try to perform a "Blind Transfer" using 
"transfer $call-id $phonenumber", the transfer fails and I get the SIP error
code "429 Provide Referrer Identity" returned from the Fritzbox. 

I suppose this is because of linphonec not sending the "Referred-By"-header. 

Is it possible to fix this bug so FRITZ!Box users can use the Blind Transfer?

-- System Information:
Debian Release: wheezy/sid
  APT prefers saucy-updates
  APT policy: (500, 'saucy-updates'), (500, 'saucy-security'), (500, 'saucy'), (100, 'saucy-backports')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.11.0-18-generic (SMP w/8 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages linphone-nogtk depends on:
ii  bind9-host [host]  1:9.9.3.dfsg.P2-4ubuntu1.1
ii  libc6              2.17-93ubuntu4
ii  liblinphone4       3.5.2-10
ii  libmediastreamer1  3.5.2-10
ii  libortp8           3.5.2-10
ii  libreadline6       6.2-9ubuntu1
ii  libx11-6           2:1.6.1-1ubuntu1
ii  linphone-common    3.5.2-10

linphone-nogtk recommends no packages.

linphone-nogtk suggests no packages.

-- no debconf information