dxgiscreencapsrc: Suppress spammy debug messages

That's not much informative debug statements for DEBUG level
29 jobs for !1504 with dxgicap-latency in 55 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Build Docker
passed #4016591
alpine amd64 manifest builder docker

00:00:32

passed #4016590
android docker

00:00:32

passed #4016589
cerbero fedora amd64 docker

00:00:33

passed #4016588
fedora amd64 docker

00:00:30

passed #4016592
gst-indent amd64 docker

00:00:26

 
  Preparation
passed #4016594
gst indent

00:00:21

manual #4016593
manual
manifest
 
  Build
created #4016603
gstreamer
build cerbero cross-android universal
created #4016607
gst-ios-13.2
build cerbero cross-ios universal
created #4016604
gstreamer
build cerbero cross win32
created #4016605
gstreamer
build cerbero cross win64
created #4016602
gstreamer
build cerbero fedora x86_64
created #4016606
gst-macos-10.15
build cerbero macos x86_64
created #4016598
build clang fedora x86_64
created #4016601
1809 windows docker allowed to fail manual
build msys2
created #4016595
build nodebug fedora x86_64
created #4016596
build static fedora x86_64
created #4016597
build static nodebug fedora x86_64
created #4016599
1809 windows docker
build vs2017 amd64
created #4016600
1809 windows docker
build vs2017 x86
 
  Test
created #4016608
gstreamer
check fedora
created #4016609
gstreamer
integration testsuites fedora 1/4
created #4016610
gstreamer
integration testsuites fedora 2/4
created #4016611
gstreamer
integration testsuites fedora 3/4
created #4016612
gstreamer
integration testsuites fedora 4/4
created #4016613
gstreamer
valgrind bad
 
  Integrate
created #4016614
cross-android universal examples
created #4016616
gst-ios-13.2
cross-ios universal examples
created #4016615
documentation