net-mgmt/virt-viewer: Remove libtool as dependency

Not used in project

Approved by:	portmgr (blanket)

net-mgmt/virt-viewer/Makefile

@@ -14,7 +14,7 @@ WWW=		https://virt-manager.org/
 LICENSE=	GPLv2
 
 USES=		cpe desktop-file-utils gettext gettext-tools gmake gnome \
-		libtool meson perl5 pkgconfig python:build \
+		meson perl5 pkgconfig python:build \
 		shared-mime-info tar:xz xorg
 CPE_VENDOR=	redhat
 USE_GNOME=	gtk30 libxml2