user-agent parameter used by RTSP tunnelling is ignored

[ioeir2]

Summary of the bug:
In RTSP over HTTP mode (tunnelling) user-agent parameter is ignored. In other RTSP modes user-agent works as expected.

How to reproduce:

./ffplay "rtsp://10.0.1.111:80/axis-media/media.amp" -rtsp_transport http -user-agent "MyUserAgent" -v 9 -loglevel 99 -i
ffplay version 2.5.git Copyright (c) 2003-2015 the FFmpeg developers
  built on Jan 18 2015 13:31:38 with Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn)
  configuration: 
  libavutil      54. 17.100 / 54. 17.100
  libavcodec     56. 20.100 / 56. 20.100
  libavformat    56. 19.100 / 56. 19.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5.  8.100 /  5.  8.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
[http @ 0x7fd61c925200] request: GET /axis-media/media.amp HTTP/1.1 
User-Agent: Lavf/56.19.100
Range: bytes=0-
Connection: close
Host: 10.0.1.111:80
Icy-MetaData: 1
x-sessioncookie: 8d35e8789d512a80
Accept: application/x-rtsp-tunnelled
Pragma: no-cache
Cache-Control: no-cache


[http @ 0x7fd61c925200] header='HTTP/1.0 200 OK'
[http @ 0x7fd61c925200] http_code=200
[http @ 0x7fd61c925200] header='Content-Type: application/x-rtsp-tunnelled'
[http @ 0x7fd61c925200] header='Date: Wed, 31 Dec 2014 22:21:08 GMT'
[http @ 0x7fd61c925200] header=''
[http @ 0x7fd61c925680] request: POST /axis-media/media.amp HTTP/1.1
User-Agent: Lavf/56.19.100
Accept: */*
Connection: close
Host: 10.0.1.111:80
Icy-MetaData: 1
x-sessioncookie: 8d35e8789d512a80
Content-Type: application/x-rtsp-tunnelled
Pragma: no-cache
Cache-Control: no-cache
Content-Length: 32767
Expires: Sun, 9 Jan 1972 00:00:00 GMT