[build] update isc-dhcp to 4.4.1-2.3+deb11u2 to fix build failure (#15002)

Why I did it
Fix #15000
isc-dhcp 4.4.1-2.3+deb11u1 is no longer available in debian repository

How I did it
update isc-dhcp to new version 4.4.1-2.3+deb11u2

rules/isc-dhcp.mk

@@ -1,7 +1,7 @@
 # isc-dhcp packages
 
 ISC_DHCP_VERSION = 4.4.1
-ISC_DHCP_VERSION_FULL = ${ISC_DHCP_VERSION}-2.3+deb11u1
+ISC_DHCP_VERSION_FULL = ${ISC_DHCP_VERSION}-2.3+deb11u2
 
 export ISC_DHCP_VERSION ISC_DHCP_VERSION_FULL
 

src/isc-dhcp/Makefile

@@ -10,7 +10,7 @@ $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
 	rm -rf ./isc-dhcp-$(ISC_DHCP_VERSION)
 
 	# Get isc-dhcp release, debian files
-	dget http://deb.debian.org/debian/pool/main/i/isc-dhcp/isc-dhcp_$(ISC_DHCP_VERSION_FULL).dsc
+	dget -u http://deb.debian.org/debian/pool/main/i/isc-dhcp/isc-dhcp_$(ISC_DHCP_VERSION_FULL).dsc
 	pushd ./isc-dhcp-$(ISC_DHCP_VERSION)
 
 	# Create a git repository here for stg to apply patches