docker/cerbero: Don't manually set ccache and parallel build

This is already set by cerbero now.

Part-of: <gstreamer/gst-ci!332>
39 jobs for dont-set-ccache-parallel-build in 27 seconds (queued for 6 seconds)
latest
Status Name Job ID Coverage
  Build Docker
passed alpine amd64 manifest builder docker #4321883

00:00:18

passed android docker #4321882

00:00:09

passed cerbero fedora amd64 docker #4321881

00:00:10

passed fedora amd64 docker #4321880

00:00:18

passed gst-indent amd64 docker #4321884

00:00:10

passed test manifest amd64 docker #4321885

00:00:10

 
  Preparation
passed gst indent #4321887

00:00:07

manual manifest #4321886
manual
passed test manifest #4321888

00:00:08

 
  Build
created build cerbero cross-android universal #4321897
gstreamer
created build cerbero cross-ios universal #4321901
gst-ios-13.2
created build cerbero cross win32 #4321898
gstreamer
created build cerbero cross win64 #4321899
gstreamer
created build cerbero fedora x86_64 #4321896
gstreamer
created build cerbero macos x86_64 #4321900
gst-macos-10.15
created build clang fedora x86_64 #4321892
created build gst-omx tizonia fedora x86_64 #4321903
created build gst-omx zynq fedora x86_64 #4321902
created build msys2 #4321895
docker windows 1809 allowed to fail manual
created build nodebug fedora x86_64 #4321889
created build static fedora x86_64 #4321890
created build static nodebug fedora x86_64 #4321891
created build vs2017 amd64 #4321893
docker windows 1809
created build vs2017 x86 #4321894
docker windows 1809
 
  Test
created check fedora #4321904
gstreamer
created integration testsuites fedora 1/4 #4321905
gstreamer
created integration testsuites fedora 2/4 #4321906
gstreamer
created integration testsuites fedora 3/4 #4321907
gstreamer
created integration testsuites fedora 4/4 #4321908
gstreamer
created valgrind bad #4321913
gstreamer
created valgrind base #4321910
gstreamer
created valgrind core #4321909
gstreamer
created valgrind ges #4321914
gstreamer
created valgrind good #4321911
gstreamer
created valgrind ugly #4321912
gstreamer
 
  Integrate
created cross-android universal examples #4321916
created cross-ios universal examples #4321918
gst-ios-13.2
created documentation #4321917
created gstreamer-full #4321915