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
gstpyramidsegment.c: In function 'gst_pyramid_segment_chain':
gstpyramidsegment.c:307:3: error: implicit declaration of function
'cvPyrSegmentation' [-Werror=implicit-function-declaration]
gstpyramidsegment.c:307:3: error: nested extern declaration of
'cvPyrSegmentation' [-Werror=nested-externs]
https://bugzilla.gnome.org/show_bug.cgi?id=687237
