isc-dhcp: fix confused description

Originally https://github.com/openwrt/packages/pull/10044

Signed-off-by: Rosen Penev <rosenp@gmail.com>

net/isc-dhcp/Makefile

@@ -10,7 +10,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=isc-dhcp
 UPSTREAM_NAME:=dhcp
 PKG_VERSION:=4.4.1
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_LICENSE:=BSD-3-Clause
 PKG_LICENSE_FILES:=LICENSE
@@ -60,7 +60,7 @@ define Package/isc-dhcp-relay/description
 endef
 
 define Package/isc-dhcp-relay-ipv4/description
-$(call Package/isc-dhcp-relay-ipv6/description)
+$(call Package/isc-dhcp-relay/description)
  This package is compiled with IPv4 support only.
 endef