net-mgmt/send: fix build with -fno-common

Declare two external variables as extern properly.
This unbreaks the build on FreeBSD 13+.
While we are at it, add missing USES=ncurses.

Approved by:	portmgr (build fix blanket)

net-mgmt/send/Makefile

@@ -1,7 +1,7 @@
 PORTNAME=	send
 PORTVERSION=	0.3
 DISTVERSIONPREFIX=	v
-PORTREVISION=	3
+PORTREVISION=	4
 CATEGORIES=	net-mgmt
 
 MAINTAINER=	hrs@FreeBSD.org
@@ -10,12 +10,9 @@ COMMENT=	Secure Neighbor Discovery implementation for IPv6
 LICENSE=	BSD3CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
-BROKEN_FreeBSD_13=	ld: error: duplicate symbol: params_linecnt
-BROKEN_FreeBSD_14=	ld: error: duplicate symbol: params_linecnt
-
 LIB_DEPENDS=	libdnet.so:net/libdnet
 
-USES=		gmake readline ssl
+USES=		gmake ncurses readline ssl
 USE_GITHUB=	yes
 GH_ACCOUNT=	hrs-allbsd
 USE_RC_SUBR=	sendd

net-mgmt/send/files/patch-libs-libpkixipext-pkixip_ext_gram.y

@@ -1,5 +1,14 @@
 --- libs/libpkixipext/pkixip_ext_gram.y.orig	2019-02-27 16:25:45 UTC
 +++ libs/libpkixipext/pkixip_ext_gram.y
+@@ -42,7 +42,7 @@
+ #include "pkixip_ext.h"
+ #include "pkixip_local.h"
+
+-int linecnt;
++extern int linecnt;
+
+ extern char *pkixip_text;
+ extern int pkixip_lex(void);
 @@ -350,7 +350,7 @@ new_aor(void)
 
  	if (!ipc->u.addressesOrRanges &&

net-mgmt/send/files/patch-sendd_params__gram.y

@@ -0,0 +1,11 @@
+--- sendd/params_gram.y.orig	2023-04-11 00:49:19 UTC
++++ sendd/params_gram.y
+@@ -77,7 +77,7 @@ static void yyerror(char *);
+ extern char *params_text;
+ extern int params_lex(void);
+
+-int params_linecnt;
++extern int params_linecnt;
+
+ static const char *derfile;
+ static const char *keyfile;