This reverts commit e457ab87f7 but the
patch is updated to match current FFmpeg.
The FFmpeg commit that seemed to do the same (7eeef72c6) is not working
correctly because it assigns idrPeriod cc->gopLength, which was set to
NVENC_INFINITE_GOPLENGTH above in case of intra-refresh.
refer to GH-330
Since the FFmpeg commit 7eeef72c6, the IDR period is set to gopLength
unconditinally even for intra-refresh mode, which is what the removed
patch did.
+ do not check if FFmpeg is patched (the macro is )
see commits e3c926c8 and 1f735a93
We patch FFmpeg in Linux CI builds so if it is patched, intra-refresh
sitll can be enabled, even though not by default.
