Remove remaining quality-analysis (QM).

This was never turned on, contains a lot of complexity and somehow
manages triggering a bug in a downstream project.

BUG=webrtc:5066
R=marpan@webrtc.org
TBR=mflodman@webrtc.org

Review URL: https://codereview.webrtc.org/1917323002 .

Cr-Commit-Position: refs/heads/master@{#12692}

webrtc/modules/video_coding/media_opt_util.h

@@ -18,7 +18,6 @@
 
 #include "webrtc/base/exp_filter.h"
 #include "webrtc/modules/video_coding/internal_defines.h"
-#include "webrtc/modules/video_coding/qm_select.h"
 #include "webrtc/system_wrappers/include/trace.h"
 #include "webrtc/typedefs.h"