games/sdlroids: fix build with -fno-common

Turn a variable definition in a header file into a declaration.
This fixes the build on FreeBSD 13+.

games/sdlroids/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	sdlroids
-PORTVERSION=	1.3.4
-PORTREVISION=	18
+DISTVERSION=	1.3.4
+PORTREVISION=	19
 CATEGORIES=	games
 MASTER_SITES=	SF \
 		SF/nemysisfreebsdp/${CATEGORIES}/:icons
@@ -16,9 +16,6 @@ WWW=		https://sourceforge.net/projects/sdlroids/
 LICENSE=	GPLv2
 LICENSE_FILE=	${WRKSRC}/COPYING
 
-BROKEN_FreeBSD_13=	ld: error: duplicate symbol: flagargs
-BROKEN_FreeBSD_14=	ld: error: duplicate symbol: flagargs
-
 USES=		gmake sdl tar:bzip2
 GNU_CONFIGURE=	yes
 CONFIGURE_ARGS=	--datadir=${PREFIX}/share

games/sdlroids/files/patch-getargs.h

@@ -0,0 +1,8 @@
+--- getargs.h.orig	2023-04-13 13:43:47 UTC
++++ getargs.h
+@@ -37,4 +37,4 @@
+ 
+ /* getargs() prototype */
+ void getargs(int, char *[]);
+-int flagargs[NUMARGS];
++extern int flagargs[NUMARGS];