[bug-recutils] recset segfaults with empty rec file

[Dominic Walden]

For example:
 $ touch test.rec
 $ recset -fRating -aExcellent test.rec
 Segmentation fault

Presumably because the function rec_db_get_rset_by_type() cannot find the
correct type.

I guess recset is not designed to be used to create recfiles from scratch.
Perhaps this condition could be caught and a message to this effect shown to the
user.

Thanks,

Dom