As previously advertised, remove the error message for enable_quotas

prior to 9.0-RELEASE.

This change should not be MFC'ed.

etc/rc.subr

@@ -1060,10 +1060,6 @@ load_rc_config()
 		. /etc/rc.conf.d/"$_name"
 	fi
 
-	# Old variable name support -- Remove before 9.0-RELEASE
-	#
-	[ -n "$enable_quotas" ] && err 1 "enable_quotas is deprecated, use quota_enable"
-
 	# Set defaults if defined.
 	for _var in $rcvar $rcvars; do
 		_defval=`eval echo "\\\$${_var}_defval"`