graphics/curtail: Remove graphics/optipng as runtime dependency

Upstream switched to Oxipng in 1.7.0

Reference:
https://github.com/Huluti/Curtail/releases/tag/1.7.0

Approved by:	portmgr (blanket, runtime dependency)

graphics/curtail/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	curtail
 DISTVERSION=	1.7.0
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	graphics print
 
 MAINTAINER=	yuri@FreeBSD.org
@@ -14,7 +14,6 @@ BUILD_DEPENDS=	appstream-util:devel/appstream-glib
 RUN_DEPENDS=	cwebp:graphics/webp \
 		jpegoptim:graphics/jpegoptim \
 		libadwaita>0:x11-toolkits/libadwaita \
-		optipng:graphics/optipng \
 		oxipng:graphics/oxipng \
 		pngquant:graphics/pngquant \
 		scour:textproc/py-scour@${PY_FLAVOR}