streamsplitter: Drop duplicated force-key-unit events

Forward force-key-unit event only once for the corresponding sequence number.
25 jobs for streamcombiner-key-unit-event in 38 minutes and 6 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Preparation
passed #572578
gst indent

00:00:35

passed #572577
manifest

00:00:46

 
  Build
passed #572588
build cerbero android universal

00:11:13

passed #572589
build cerbero cross win32

00:08:14

passed #572590
build cerbero cross win64

00:07:21

passed #572587
build cerbero fedora x86_64

00:06:46

manual #572592
gst-ios-12.2 allowed to fail manual
build cerbero ios universal
passed #572591
gst-macos-10.14
build cerbero macos x86_64

00:07:39

passed #572583
build clang fedora x86_64

00:06:54

passed #572579
build fedora x86_64

00:05:23

passed #572586
1607 windows docker
build msys2

00:12:52

passed #572580
build nodebug fedora x86_64

00:03:40

passed #572581
build static fedora x86_64

00:12:23

passed #572582
build static nodebug fedora x86_64

00:03:24

passed #572584
1607 windows docker
build vs2017 amd64

00:10:48

passed #572585
1607 windows docker
build vs2017 x86

00:11:29

 
  Test
passed #572593
check fedora

00:04:31

passed #572594
integration testsuites fedora

00:15:40

passed #572598
valgrind bad

00:08:58

passed #572595
valgrind base

00:09:37

passed #572599
valgrind ges

00:07:40

passed #572596
valgrind good

00:12:20

passed #572597
valgrind ugly

00:03:29

 
  Integrate
passed #572600
android universal examples

00:09:46

passed #572601
documentation

00:04:36