mail/cyrus-imapd25: Make it buildable with db18 on recent FreeBSD.

mail/cyrus-imapd25/Makefile

@@ -157,6 +157,12 @@ CYRUS_MAN8+=	ctl_zoneinfo httpd
 CYRUS_MAN8+=	fetchnews nntpd
 .endif
 
+.include <bsd.port.pre.mk>
+
+.if ${OPSYS} == FreeBSD && ( ${OSVERSION} >= 1400091 || ( ${OSVERSION} >= 1302507 && ${OSVERSION} < 1400000 ))
+CFLAGS+=	-Wno-error=incompatible-function-pointer-types
+.endif
+
 post-patch:
 	@${REINPLACE_CMD} -e "s|/etc/|${PREFIX}/etc/|" \
 			  -e "s|%%CYRUS_USER%%|${CYRUS_USER}|g" \
@@ -209,4 +215,4 @@ post-install-EXAMPLES-on:
 	@${ECHO_CMD} ${EXAMPLESDIR:S,^${PREFIX}/,,}/${f} >>${TMPPLIST}
 .endfor
 
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>