avformat/utils: av_probe_input_buffer2 decrease difference to libav

This removes the initialization of 2 unused fields
The change was part of c1868e7ee7b07b40a0fe15f50df89fe499a01a50
but wasnt merged as the fields could still be used

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/librtmp: Fix memory leak if RTMP_ConnectStream() fails

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