[build] Fix isc-dhcp full version in rules.mk (sonic-net#13288)

During the build process, a dsc file is retrieved from the URL:
http://deb.debian.org/debian/pool/main/i/isc-dhcp/isc-dhcp_4.4.1-2.3.dsc

Depending on the DNS resolution, the server reached may respond with a
HTTP 404 error code, what stops the build process.
In all cases, the URL http://deb.debian.org/debian/pool/main/i/isc-dhcp/
no more lists this DSC file but one with a different format.

The suffix "+deb11u1" is now appended to identify the debian version.

- append this suffix to the make file rules of isc-dhcp

Signed-off-by: Guillaume Lambert <guillaume.lambert@orange.com>

Author: guillaumelambert

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
+ISC_DHCP_VERSION_FULL = ${ISC_DHCP_VERSION}-2.3+deb11u1
 
 export ISC_DHCP_VERSION ISC_DHCP_VERSION_FULL