media-video/rav1e: fix build with >=libgit2-1.8.0

libgit2-sys crate has a upper bound for <1.8.0 and refuses
to build otherwise, but not seeing(?) any issues with it.

Just a quick emergency fix, will likely be fixed next libgit2-sys
version. Kept full version in the sed's path rather than a glob
to force re-checking this when the crate is bumped.

Alternatively could drop LIBGIT2_NO_VENDOR or set an upper bound
in RDEPEND, but does not seem necessary.

Note 9999 is still broken albeit hopefully the crate will just be
fixed upstream in time. 9999 users could keep old libgit2 meanwhile.

Signed-off-by: Ionen Wolkens <ionen@gentoo.org>

media-video/rav1e/rav1e-0.7.1.ebuild

@@ -281,6 +281,14 @@ src_unpack() {
 	fi
 }
 
+src_prepare() {
+	default
+
+	# libgit2-sys unnecessarily(?) requests <libgit2-1.8.0, bump to 2 for now
+	sed -e '/range_version/s/1\.8\.0/2/' \
+		-i "${ECARGO_VENDOR}"/libgit2-sys-0.16.1+1.7.1/build.rs || die
+}
+
 src_compile() {
 	# used by build script to get rav1e repository info
 	export LIBGIT2_NO_VENDOR=1