multimedia/svt-av1: add new license after a8dd5511

https://github.com/AOMediaCodec/SVT-AV1/commit/9272e132a3cd

multimedia/svt-av1/Makefile

@@ -6,10 +6,11 @@ CATEGORIES=	multimedia
 MAINTAINER=	jbeich@FreeBSD.org
 COMMENT=	Scalable AV1 encoder
 
-LICENSE=	BSD2CLAUSE BSD3CLAUSE
+LICENSE=	BSD2CLAUSE BSD3CLAUSE MIT
 LICENSE_COMB=	multi
 LICENSE_FILE_BSD2CLAUSE=	${WRKSRC}/LICENSE.md
 LICENSE_FILE_BSD3CLAUSE=	${WRKSRC}/third_party/fastfeat/LICENSE
+LICENSE_FILE_MIT=		${WRKSRC}/third_party/safestringlib/LICENSE
 
 BROKEN_i386=	https://gitlab.com/AOMediaCodec/SVT-AV1/-/issues/1231