biology/emboss: Optionize mysql support

The port builds fine without mysql and as MySQL57 is reaching end of
life so optionize MYSQL so that other flavors can be used and still
there is an available pkg for this port.

Approved by:	portmgr (blanket)

biology/emboss/Makefile

 PORTNAME=	emboss
 PORTVERSION=	6.6.0
-PORTREVISION=	6
+PORTREVISION=	7
 CATEGORIES=	biology
 MASTER_SITES=	ftp://emboss.open-bio.org/pub/EMBOSS/
 DISTNAME=	${PORTNAME:tu}-${PORTVERSION}
@@ -17,8 +17,7 @@ BUILD_DEPENDS=	clustalw:biology/clustalw \
 LIB_DEPENDS=	libgd.so:graphics/gd \
 		libpng.so:graphics/png
 
-USES=		gmake libtool iconv mysql pgsql ssl
-IGNORE_WITH_MYSQL=	80
+USES=		gmake libtool iconv localbase:ldflags pgsql ssl
 USE_SUBMAKE=	yes
 
 CONFLICTS=	qmail-ldap digest
@@ -29,16 +28,18 @@ GNU_CONFIGURE=	yes
 USE_LDCONFIG=	yes
 SUB_FILES=	pkg-message emboss-shell
 SUB_LIST=	PREFIX=${PREFIX} DATADIR=${DATADIR}
-LDFLAGS+=	-L${LOCALBASE}/lib
 CONFIGURE_ARGS+=${ICONV_CONFIGURE_ARG}
 INSTALL_TARGET=	install-strip
 
 DOCSDIR=	${PREFIX}/share/${PORTNAME:tu}/doc
 DATADIR=	${PREFIX}/share/${PORTNAME:tu}
 
-OPTIONS_DEFINE=	DOCS X11
+OPTIONS_DEFINE=	DOCS MYSQL X11
 OPTIONS_DEFAULT=	X11
+
 DOCS_CONFIGURE_ON=	--with-docroot=${DOCSDIR}
+MYSQL_USES=	mysql
+MYSQL_VARS=	IGNORE_WITH_MYSQL=80
 X11_USES=	motif xorg
 X11_USE=	XORG=x11
 X11_LIB_DEPENDS=	libgd.so:graphics/gd \