isc-dhcp: drop .conf suffix on dhcrelay config file

Resolves issue #7235

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.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:=2
+PKG_RELEASE:=3
 
 PKG_LICENSE:=BSD-3-Clause
 PKG_LICENSE_FILES:=LICENSE
@@ -196,7 +196,7 @@ define Package/isc-dhcp-relay-$(BUILD_VARIANT)/install
 	$(INSTALL_DIR) $(1)/usr/sbin
 	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/dhcrelay $(1)/usr/sbin
 	$(INSTALL_DIR) $(1)/etc/config
-	$(INSTALL_DATA) ./files/dhcrelay.conf $(1)/etc/config
+	$(INSTALL_DATA) ./files/dhcrelay.conf $(1)/etc/config/dhcrelay
 	$(INSTALL_DIR) $(1)/etc/init.d
 	$(INSTALL_BIN) ./files/dhcrelay4.init $(1)/etc/init.d/dhcrelay4
 endef