rtpjitterbuffer: don't calculate packet-rate for jumping seqnums

As demonstrated by the test, you can end up in situations where
your packet-rate gets insanly high, and you produce thousands of RTX-timers
/lost events, when the big-gap logic is there to prevent exactly that.
27 jobs for !570 with hgr/jb-no-packet-rate-for-jumping-seqnum in 68 minutes and 22 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Preparation
passed #2313578
gst indent

00:00:27

passed #2313577
manual
manifest

00:00:36

 
  Build
passed #2313597
gstreamer
build cerbero cross-android universal

00:08:18

passed #2313605
gst-ios-13.2
build cerbero cross-ios universal

01:02:59

passed #2313599
gstreamer
build cerbero cross win32

00:06:37

passed #2313602
gstreamer
build cerbero cross win64

00:03:09

passed #2313595
gstreamer
build cerbero fedora x86_64

00:03:12

passed #2313604
gst-macos-10.15
build cerbero macos x86_64

00:11:15

passed #2313587
build clang fedora x86_64

00:05:46

passed #2313580
build fedora x86_64

00:05:27

manual #2313593
docker windows 1809 allowed to fail manual
build msys2
passed #2313582
build nodebug fedora x86_64

00:04:19

passed #2313583
build static fedora x86_64

00:05:46

passed #2313585
build static nodebug fedora x86_64

00:03:23

passed #2313588
docker windows 1809
build vs2017 amd64

00:13:06

manual #2313591
docker windows 1809 allowed to fail manual
build vs2017 x86
 
  Test
failed #2313606
gstreamer
check fedora

00:03:30

passed #2313607
gstreamer
integration testsuites fedora 1/4

00:12:17

passed #2313608
gstreamer
integration testsuites fedora 2/4

00:13:00

passed #2313609
gstreamer
integration testsuites fedora 3/4

00:14:40

passed #2313610
gstreamer
integration testsuites fedora 4/4

00:13:03

failed #2313612
gstreamer
valgrind bad

00:07:49

passed #2313613
gstreamer
valgrind ges

00:07:52

failed #2313611
gstreamer
valgrind good

00:34:47

 
  Integrate
passed #2313614
cross-android universal examples

00:04:44

passed #2313616
gst-ios-13.2
cross-ios universal examples

00:04:13

passed #2313615
documentation

00:03:49

 
Name Stage Failure
failed
valgrind good Test
Uploading artifacts for failed job
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files

validate-logs: found 1603 matching files

Uploading artifacts to coordinator... ok
id=2313611 responseStatus=201 Created token=bRjXCywc
Uploading artifacts...
validate-logs/*.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=2313611 responseStatus=201 Created token=bRjXCywc
ERROR: Job failed: exit code 1
failed
valgrind bad Test
Uploading artifacts for failed job
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files

validate-logs: found 913 matching files

Uploading artifacts to coordinator... ok
id=2313612 responseStatus=201 Created token=Ssn4Kj_K
Uploading artifacts...
validate-logs/*.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=2313612 responseStatus=201 Created token=Ssn4Kj_K
ERROR: Job failed: exit code 1
failed
check fedora Test
Uploading artifacts for failed job
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files

validate-logs: found 3781 matching files

Uploading artifacts to coordinator... ok
id=2313606 responseStatus=201 Created token=iY4emYGx
Uploading artifacts...
validate-logs/*.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=2313606 responseStatus=201 Created token=iY4emYGx
ERROR: Job failed: exit code 1