srt_compat.h: Enable localtime_s only if MSC_VER >= 1500
srt_compat.h: Enable localtime_s only if MSC_VER >= 1500

Signed-off-by: Justin Kim <cdb6e3da7948960ce0d2749c9c9c4d2a2feaeeb4@collabora.com>

Haivision/srt,Cinegy/srt,ethouris/srt,Haivision/srt,Haivision/srt,Haivision/srt,Cinegy/srt,ethouris/srt,ethouris/srt,ethouris/srt,Cinegy/srt,Cinegy/srt