Better fix for "spectrogram.c: Fix an out-of-bounds access"

[martinwguy]

This reverts commit 91a7041,
which leaves a strip of black pixels at the top of the graph
visible only with --no-border, and makes a better fix for the same issue.

[erikd]

Awesome. Thanks!

[martinwguy]

Thanks to you!

BTW, you asked me some time ago for any ways you could be a more
effective OS project lead.
I can't say I have much experience or success in that field - I tend
to find myself developing my own bright ideas, maintaining other
people's abandonware or contributing little fixes to other projects -
but there is an excellent book on the subect, Producing Open Source
Software at producingoss.com which explores the area pretty well,
based on the experience of the Subversion project leads. Readable
online (but I bought a copy to read more easily). Whatever you may
think of SVN itself, his outline of the various mechanisms that are
used in OS development, and the interpersonal issues that arise, are
all valid.

Cheers

M