graphics/gimp-app: chase math/Imath update

...and remove the Imath version from its LIB_DEPENDS,
since Imath is only included indirectly through openexr,
so gimp-app need not care about details.

graphics/gimp-app/Makefile

@@ -2,7 +2,7 @@
 
 PORTNAME?=	gimp-app
 PORTVERSION=	2.10.24
-PORTREVISION=	8
+PORTREVISION=	9
 PORTEPOCH?=	1
 CATEGORIES?=	graphics gnome
 MASTER_SITES=	GIMP/gimp/v${PORTVERSION:R}
@@ -118,7 +118,7 @@ LIBMNG_LIB_DEPENDS=	libmng.so:graphics/libmng
 LIBMNG_CONFIGURE_WITH=	libmng
 
 OPENEXR_CONFIGURE_WITH=	openexr
-OPENEXR_LIB_DEPENDS=	libImath-3_0.so:math/Imath \
+OPENEXR_LIB_DEPENDS=	libImath.so:math/Imath \
 			libOpenEXR.so:graphics/openexr
 
 OPENJPEG_DESC=		Enhanced JPEG (jpeg2000) graphics support