This adds some spacing to the version struct, so that astyle won't
need to change the file.
This was changed in 02354832cf8, both in the earlier codec_ver.h
and in the script that generates it, but a recent change manually
overwrote the spacing.
Previously, the variable itself wasn't const (which meant that
it could be set to point to another const string instead).
By declaring it as const, gcc doesn't warn about it being unused,
and we can get rid of a workaround.
