Certain SBR AAC tracks only have two-bytes long codec-specific
configuration data even though SBR normally requires five-bytes long
data. mkvmerge contains a heuristic for such cases that treats sampling
frequencies of <= 24000 Hz as another indicator for SBR.
However, this breaks in cases of low sampling frequencies like 8000 Hz
which are almost never SBR. This results in the wrong profile being
detected preventing mkvmerge from appending such tracks to track for
which the profile was detected correctly.
This change limits the heuristic to the two most common sampling
frequencies used for such broken SBR AAC files: 22050 Hz and 24000 Hz.
Fixes#1540.
