coreutils: fixed to not install kill(1) if util-linux is available

Note:

Starting with util-linux 2.22 the kill(1) command will be installed
default!

base/coreutils/coreutils.conf

@@ -62,7 +62,7 @@ hook_add postmake 5 'ln -sf install $root/usr/bin/ginstall'
 var_append confopt ' ' '--enable-install-program=hostname'
 
 noinstall=
-for x in mktemp procps:uptime; do
+for x in mktemp procps:uptime util-linux:kill; do
 	if pkginstalled "${x%:*}"; then
 		var_append noinstall ',' "${x#*:}"
 	fi