rtmphttp: Check for both 0 and AVERROR_EOF

This makes RTMPT work again - it was broken by 5d876be87a.

Signed-off-by: Martin Storsjö <martin@martin.st>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  rtmphttp: Check for both 0 and AVERROR_EOF

Conflicts:
	libavformat/rtmphttp.c

See: d04b7de786780747878c080ba522405c6f542ccb
Merged-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mpegts: fix resync seek

The seek ended up seeking before the begin, which caused problems
Fixes initial sync issues with libbluray
Fixes Ticket3117

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>