rtspsrc: Correctly parse RTSP 2.0 RTP-Info headers

These are actually different from RTSP 1.0 ones and failed to parse
before. As gst-rtsp-server produces RTSP 1.0 RTP-Info headers, still
handle parsing them for RTSP 2.0.

Fixes gstreamer/gst-plugins-good#834
32 jobs for rtspsrc-rtsp2-rtp-info in 54 seconds (queued for 3 seconds)
latest
Status Job ID Name Coverage
  Build Docker
passed #6846425
alpine amd64 manifest builder docker

00:00:39

passed #6846424
android docker

00:00:32

passed #6846423
cerbero fedora amd64 docker

00:00:32

passed #6846422
fedora amd64 docker

00:00:32

passed #6846426
gst-indent amd64 docker

00:00:29

 
  Preparation
passed #6846428
gst indent

00:00:12

manual #6846427
manual
manifest
 
  Build
created #6846437
gstreamer
build cerbero cross-android universal
created #6846441
gst-ios-14.3
build cerbero cross-ios universal
created #6846438
gstreamer
build cerbero cross win32
created #6846439
gstreamer
build cerbero cross win64
created #6846436
gstreamer
build cerbero fedora x86_64
created #6846440
gst-macos-11.1
build cerbero macos x86_64
created #6846442
docker windows 1809 gstreamer-windows
build cerbero msvc x86_64
created #6846432
build clang fedora x86_64
created #6846435
docker windows 1809 allowed to fail manual
build msys2
created #6846429
build nodebug fedora x86_64
created #6846430
build static fedora x86_64
created #6846431
build static nodebug fedora x86_64
created #6846433
docker windows 1809
build vs2017 amd64
created #6846434
docker windows 1809
build vs2017 x86
 
  Test
created #6846443
gstreamer
check fedora
created #6846444
gstreamer
integration testsuites fedora 1/4
created #6846445
gstreamer
integration testsuites fedora 2/4
created #6846446
gstreamer
integration testsuites fedora 3/4
created #6846447
gstreamer
integration testsuites fedora 4/4
created #6846449
gstreamer
valgrind bad
created #6846450
gstreamer
valgrind ges
created #6846448
gstreamer
valgrind good
 
  Integrate
created #6846451
cross-android universal examples
created #6846453
gst-ios-14.3
cross-ios universal examples
created #6846452
documentation