Fix parsing bitrate without greek characters

[nullptr-0]

Output should not be truncated when no greek characters.

[coveralls]

coverage: 98.826%. remained the same when pulling 26e0e14c2c084979512d472526280178a747a5f0 on nullptr-0:master into 434290765a4e698bf88d6d3752260df3eb24bf18 on rabitt:master.

[lostanlen]

Thanks. I think this line is untested at the moment 😳

From what i see, testing this branch would require an extra audio file with no Greek suffix in the bitrate?