Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
The last argument of dbm_open() should be a mode_t according to POSIX;
not an int.
Reviewed by: pfg, kib
Differential Revision: https://reviews.freebsd.org/D6650