cccombiner: Update segment according to video sink pad

Otherwise the following pipeline would preroll after 1000 hours:
gst-launch-1.0 videotestsrc ! x264enc ! cccombiner ! fakesink silent=0 sync=1 -v

Fixes #1355

Part-of: <!1419>
29 jobs for master in 54 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Build Docker
passed #3513766
alpine amd64 manifest builder docker

00:00:22

passed #3513765
android docker

00:00:26

passed #3513764
cerbero fedora amd64 docker

00:00:20

passed #3513763
fedora amd64 docker

00:00:20

passed #3513767
gst-indent amd64 docker

00:00:33

 
  Preparation
passed #3513769
gst indent

00:00:19

manual #3513768
manual
manifest
 
  Build
created #3513778
gstreamer
build cerbero cross-android universal
created #3513782
gst-ios-13.2
build cerbero cross-ios universal
created #3513779
gstreamer
build cerbero cross win32
created #3513780
gstreamer
build cerbero cross win64
created #3513777
gstreamer
build cerbero fedora x86_64
created #3513781
gst-macos-10.15
build cerbero macos x86_64
created #3513773
build clang fedora x86_64
created #3513776
1809 windows docker allowed to fail manual
build msys2
created #3513770
build nodebug fedora x86_64
created #3513771
build static fedora x86_64
created #3513772
build static nodebug fedora x86_64
created #3513774
1809 windows docker
build vs2017 amd64
created #3513775
1809 windows docker
build vs2017 x86
 
  Test
created #3513783
gstreamer
check fedora
created #3513784
gstreamer
integration testsuites fedora 1/4
created #3513785
gstreamer
integration testsuites fedora 2/4
created #3513786
gstreamer
integration testsuites fedora 3/4
created #3513787
gstreamer
integration testsuites fedora 4/4
created #3513788
gstreamer
valgrind bad
 
  Integrate
created #3513789
cross-android universal examples
created #3513791
gst-ios-13.2
cross-ios universal examples
created #3513790
documentation