If old opencv1-style legacy include directory is available,
this change becomes purely cosmetic (maybe will compile a bit faster).
It becomes an FTBFS fix when opencv1-style include directory is missing
(possibly because opencv package maintainer decided not to pack it).
https://bugzilla.gnome.org/show_bug.cgi?id=747705
Fixes:
In file included from gstsegmentation.h:51:0,
from gstopencv.c:42:
/usr/include/opencv2/video/background_segm.hpp:47:16: fatal error: list:
No such file or directory
#include <list>
^
compilation terminated.
https://bugzilla.gnome.org/show_bug.cgi?id=702297