security/git-crypt: fix build with GCC-based architectures

Add USES=compiler:c++11-lang.

Don't add -L${OPENSSLLIB} unconditionally, do it only when SSL library from ports is used. The reason is that adding -L/usr/lib makes ports GCC want to link to libstdc++ from /usr/lib, not from /usr/local/lib/gcc8. This causes linking errors

PR:		237525
Approved by:	ashish (maintainer), tcberner (mentor)
Differential Revision:	https://reviews.freebsd.org/D20053

security/git-crypt/Makefile

@@ -18,8 +18,6 @@ RUN_DEPENDS=	git:devel/git \
 
 OPTIONS_DEFINE=	MANPAGES
 
-CXXFLAGS+=	-I${OPENSSLINC}
-LDFLAGS+=	-L${OPENSSLLIB}
 MAKE_ENV+=	PREFIX=${PREFIX} "CXXFLAGS=${CXXFLAGS}" \
 		"LDFLAGS=${LDFLAGS}"
 
@@ -30,10 +28,17 @@ MANPAGES_MAKE_ARGS=		ENABLE_MAN=yes \
 			DOCBOOK_XSL=${LOCALBASE}/share/xsl/docbook/manpages/docbook.xsl
 MANPAGES_PLIST_FILES=	man/man1/${PORTNAME}.1.gz
 
-USES=		gmake ssl
+USES=		compiler:c++11-lang gmake ssl
 
 PLIST_FILES=	bin/${PORTNAME}
 
+.include <bsd.port.pre.mk>
+
+.if ${SSL_DEFAULT} != base
+CXXFLAGS+=	-I${OPENSSLINC}
+LDFLAGS+=	-L${OPENSSLLIB}
+.endif
+
 post-extract:
 	@${GREP} -Rl '"gpg"' ${WRKSRC} |${XARGS} ${REINPLACE_CMD} -e 's,"gpg","${LOCALBASE}/bin/gpg",'
 	@${GREP} -Rl '"git"' ${WRKSRC} |${XARGS} ${REINPLACE_CMD} -e 's,"git","${LOCALBASE}/bin/git",'
@@ -41,4 +46,4 @@ post-extract:
 post-install:
 	${STRIP_CMD} ${STAGEDIR}${PREFIX}/bin/git-crypt
 
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>