oops, a chown appears late on the code. to satisfy this pledge

oops, a chown appears late on the code.  to satisfy this pledge
"stdio rpath wpath cpath getpw fattr proc" early on; "proc fattr"
allows doing work with other uids on the file.  after opening the
db, do the chown (replace with fchown since we know fd) and then
pledge "stdio rpath"; "rpath" due to tmpfile rename() at the end.
mistake spotted by mpi