ports/151115: mail/mutt should be updated to 1.4.2.3 to fix security bugs

[Bruce Cran]

Sorry, I got confused by the PATCHVERSION line - for some reason it's
not been updated and I saw that instead of PORTVERSION:

PATCHVERSION?=	${PORTVERSION}
PATCHVERSION=	1.4.2.2

I presume it will be building 1.4.2.3 though so this PR can be closed.

-- 
Bruce Cran