rtsp-stream: use mcast_udpsink[0] last-sample if available for rtpinfo

Otherwise no sink is found for multicast sreams and the less accurate
fallback is used to determine the current sequence number and timestamp.
27 jobs for !112 with mcast-rtpinfo in 54 minutes and 39 seconds (queued for 5 seconds)
detached
Status Job ID Name Coverage
  Preparation
passed #2113029
gst indent

00:00:26

passed #2113028
manifest

00:00:36

 
  Build
passed #2113039
gstreamer
build cerbero cross-android universal

00:12:35

passed #2113043
gst-ios-13.2
build cerbero cross-ios universal

00:17:07

passed #2113040
gstreamer
build cerbero cross win32

00:09:05

passed #2113041
gstreamer
build cerbero cross win64

00:08:11

passed #2113038
gstreamer
build cerbero fedora x86_64

00:03:46

passed #2113042
gst-macos-10.15
build cerbero macos x86_64

00:09:57

passed #2113034
build clang fedora x86_64

00:08:12

passed #2113030
build fedora x86_64

00:08:00

manual #2113037
docker windows 1809 gstreamer-windows allowed to fail manual
build msys2
passed #2113031
build nodebug fedora x86_64

00:05:18

passed #2113032
build static fedora x86_64

00:13:51

passed #2113033
build static nodebug fedora x86_64

00:04:32

passed #2117240
docker windows 1809 gstreamer-windows
build vs2017 amd64

00:11:36

manual #2113036
docker windows 1809 gstreamer-windows allowed to fail manual
build vs2017 x86
failed #2113035
docker windows 1809 gstreamer-windows
build vs2017 amd64

00:04:00

failed #2113177
docker windows 1809 gstreamer-windows
build vs2017 amd64

01:55:41

failed #2115697
docker windows 1809 gstreamer-windows
build vs2017 amd64

00:06:14

 
  Test
passed #2113044
gstreamer
check fedora

00:03:56

passed #2113045
gstreamer
integration testsuites fedora 1/4

00:13:29

passed #2113046
gstreamer
integration testsuites fedora 2/4

00:18:15

passed #2113047
gstreamer
integration testsuites fedora 3/4

00:12:31

passed #2113048
gstreamer
integration testsuites fedora 4/4

00:14:36

 
  Integrate
passed #2113049
cross-android universal examples

00:10:05

passed #2113051
gst-ios-13.2
cross-ios universal examples

00:03:36

passed #2113050
documentation

00:04:11