Disable stupid mutt configure check for /var/mail on build machine.

Index: mail/mutt-devel/Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/mail/mutt-devel/Makefile,v
retrieving revision 1.93
diff -p -u -r1.93 Makefile
--- mail/mutt-devel/Makefile	9 Mar 2013 22:15:08 -0000	1.93
+++ mail/mutt-devel/Makefile	23 Apr 2013 13:29:18 -0000
@@ -47,6 +47,11 @@ CONFIGURE_ARGS+=	--without-wc-funcs
 CONFIGURE_ARGS+=	--with-exec-shell=/bin/ksh
 .endif
 
+# Work around a stupid botch whereby mutt checks whether the *build*
+# host's /var/mail or /var/spool/mail exists in order to statically
+# decide where to read mail from.  Seriously?
+CONFIGURE_ARGS+=	--with-homespool=yes
+
 .include "options.mk"
 
 LDFLAGS+=		${_STRIPFLAG_CC}