The documentation writes the output should be "each line containing a
tab separated address then name then some other optional information".
The wiki page at
<https://gitlab.com/muttmua/mutt/-/wikis/MuttGuide/Aliases> also
implies a single tab between each field.

Since the function used strtok, consecutive tab delimeters were
treated as a single delimiter.  This caused a missing name field to
use the comment field as the name.

Change the function to use strchr instead.  This is not without risk,
as the functionality is old.  Who knows what all programs have been
written that might assume initial, or multiple delimiters are
acceptable...

Thanks to Magnus Groß for reporting the problem along with a patch,
which this commit is derived from.