aggregator: Consider the LATENCY query successful if at least one peer succeeded

Otherwise what can happen is the following: Consider two live sources,
and one of the live sources can only answer the latency query once it
has data to forward. This might take a few seconds, while the other
source is already ready to produce data.

Aggregator would now do a latency query once the early source produced
data, fail the query and then wait forever until the late source is also
producing data. Only then it would do a latency query again, which would
now succeed. Aggregator would have waited longer than the latency
deadline of the early source and would have dropped a lot of data
unnecessarily while waiting for the late source, but instead it could've
already output data for the early source.
34 jobs for !1166 with rebase-MR-356-on-1.18 in 4 minutes and 9 seconds (queued for 1 minute and 25 seconds)
latest detached
Status Name Job ID Coverage
  Build Docker
passed alpine amd64 manifest builder docker #14783699

00:01:31

passed android docker #14783697

00:01:18

passed cerbero fedora amd64 docker #14783696

00:01:22

passed fedora amd64 docker #14783694

00:01:23

passed gst-indent amd64 docker #14783701

00:01:24

 
  Preparation
passed gst indent #14783705

00:01:26

manual manifest #14783703
manual
 
  Build
created build cerbero cross-android universal #14783723
gstreamer
created build cerbero cross-ios universal #14783727
gst-ios-14.3
created build cerbero cross win32 #14783724
gstreamer
created build cerbero cross win64 #14783725
gstreamer
created build cerbero fedora x86_64 #14783722
gstreamer
created build cerbero macos x86_64 #14783726
gst-macos-11.1
created build clang fedora x86_64 #14783713
created build msys2 #14783721
docker windows 1809 allowed to fail manual
created build nodebug fedora x86_64 #14783707
created build static fedora x86_64 #14783709
created build static nodebug fedora x86_64 #14783711
created build vs2017 amd64 #14783715
docker windows 1809
created build vs2017 x86 #14783718
docker windows 1809
 
  Test
created check fedora #14783728
gstreamer
created integration testsuites fedora 1/4 #14783729
gstreamer
created integration testsuites fedora 2/4 #14783730
gstreamer
created integration testsuites fedora 3/4 #14783731
gstreamer
created integration testsuites fedora 4/4 #14783732
gstreamer
created valgrind bad #14783737
gstreamer
created valgrind base #14783734
gstreamer
created valgrind core #14783733
gstreamer
created valgrind ges #14783738
gstreamer
created valgrind good #14783735
gstreamer
created valgrind ugly #14783736
gstreamer
 
  Integrate
created cross-android universal examples #14783739
created cross-ios universal examples #14783741
gst-ios-14.3
created documentation #14783740