AVI audio: sample size NEQ block align

[cgbug]

Sample:
​https://www.datafilehost.com/d/db49c6d6

MediaInfo says it contains PCM (LE, 8kHz)

ffmpeg version N-89672-g41e51fbcd9 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7.2.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-amf --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx
  libavutil      56.  7.100 / 56.  7.100
  libavcodec     58.  9.100 / 58.  9.100
  libavformat    58.  3.100 / 58.  3.100
  libavdevice    58.  0.100 / 58.  0.100
  libavfilter     7.  8.100 /  7.  8.100
  libswscale      5.  0.101 /  5.  0.101
  libswresample   3.  0.101 /  3.  0.101
  libpostproc    55.  0.100 / 55.  0.100
[avi @ 000000000053fc00] sample size (8000) != block align (2)
[avi @ 000000000053fc00] Something went wrong during header parsing, tag [16][0][0][0] has size 1414744396, I will ignore it and try to continue anyway.
[avi @ 000000000053fc00] Could not find codec parameters for stream 1 (Audio: none ([1][0][0][0] / 0x0001), 8000 Hz, 1 channels, 128 kb/s): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, avi, from 'sample.avi':
  Duration: 00:00:09.33, start: 0.000000, bitrate: 898 kb/s
    Stream #0:0: Video: h264 (Main) (H264 / 0x34363248), yuv420p(progressive), 1280x720, 15 fps, 15 tbr, 15 tbn, 30 tbc
    Stream #0:1: Audio: none ([1][0][0][0] / 0x0001), 8000 Hz, mono, 128 kb/s

[Carl Eugen Hoyos]

Regression since d7b20bfb / 261e9348