graphics/Coin: unbreak fetch

A fork can be renamed or deleted, so get PR commits via upstream.

fetch: https://github.com/unrelentingtech/coin/commit/3053d28b74d.patch: Not Found
fetch: https://github.com/coin3d/coin/commit/3053d28b74d.patch: size mismatch: expected 1408, actual 1410

-index 6c039a0a3..007461cbd 100644
+index 6c039a0a36..007461cbd4 100644

graphics/Coin/Makefile

@@ -4,7 +4,7 @@ DISTVERSIONPREFIX=	Coin-
 PORTREVISION=	4
 CATEGORIES=	graphics
 
-PATCH_SITES=	https://github.com/unrelentingtech/coin/commit/
+PATCH_SITES=	https://github.com/${GH_ACCOUNT}/${GH_PROJECT}/commit/
 PATCHFILES+=	3053d28b74d.patch:-p1 # Unbreak non-X11
 
 MAINTAINER=	cmt@FreeBSD.org

graphics/Coin/distinfo

 TIMESTAMP = 1595369132
 SHA256 (coin3d-coin-Coin-4.0.0_GH0.tar.gz) = b00d2a8e9d962397cf9bf0d9baa81bcecfbd16eef675a98c792f5cf49eb6e805
 SIZE (coin3d-coin-Coin-4.0.0_GH0.tar.gz) = 6788294
-SHA256 (3053d28b74d.patch) = 0fad01632d6a50d63f6d846ba45571b497261aec122def5d42d64025ac37582a
-SIZE (3053d28b74d.patch) = 1408
+SHA256 (3053d28b74d.patch) = 8514418b7da2f11a14d03e77821a18a9050494c35ff6c08e1e56e4a811b815be
+SIZE (3053d28b74d.patch) = 1410