man: move "myhostname" right after "resolve"

man: move "myhostname" right after "resolve"

The text in the man page provides the justification why I think this is
generally the right thing. An additional reason is that with the previous
commit (to move resolved earlier), since resolved internally implements the
same rules that nss-myhostname does, we'd have this strange inversion where
the priority of external configuration would be different in the "resolve"
path and in the fallback path.