If a user wishes to change a password on a system running YP, and
the master server is not running rpc.yppasswdd, chpass(1) would fail,
even if the user had a local entry. Fix this by checking for local
entry if master is not running rpc.yppasswd iff we defaulted to using
YP (not invoked with "-y").
XXX Unlike the similar change to passwd(1), this one duplicates some
XXX code (makes an attempt to contact rpc.yppasswdd early). This is
XXX a side-effect of the structure of this program. chpass(1) could
XXX use a re-write.
YP server. This is required if the passwd database is to stay in sync
if this program is run on the YP server. Note, local passwd database
operations can still be performed by passing the -l flag.
