Fix tutorial01

[tetsu-koba]

AvErrorEAGAIN value is -35 now. I wonder -11 is proper value.

And changed tutorial01.go and it works fine.

close #75

[wargebitebane]

Now its writing two frames then crashes (but before fix frame was only one)

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '.\not-fragmented.mp4':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
creation_time : 2020-06-22T06:56:59.000000Z
Duration: 00:01:18.20, start: 0.000000, bitrate: 16207 kb/s
Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 162 kb/s (default)
Metadata:
creation_time : 2020-06-22T06:56:59.000000Z
handler_name : Sound Media Handler
Stream #0:1(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(bt709, top coded first (swapped)), 1920x1080 [SAR 1:1 DAR 16:9], 15931 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc (default)
Metadata:
creation_time : 2020-06-22T06:57:00.000000Z
handler_name : Video Media Handler
timecode : 09:56:59:17
Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
Metadata:
creation_time : 2020-06-22T06:57:00.000000Z
handler_name : Time Code Media Handler
timecode : 09:56:59:17
Didn't find a video stream
Writing frame 1
Writing frame 2
exit status 3221226356