Fix/amend DHCP client detection (#513)

- dhcpd is a server; the client is dhcpcd

- While here, add udhcpc to the list of recognised DHCP clients

include/tests_networking

@@ -574,7 +574,7 @@
     # Description : Checking for DHCP client
     Register --test-no NETW-3030 --weight L --network NO --category security --description "Checking DHCP client status"
     if [ ${SKIPTEST} -eq 0 ]; then
-        IsRunning dhclient || IsRunning dhcpd
+        IsRunning dhclient || IsRunning dhcpcd || IsRunning udhcpc
         if [ ${RUNNING} -eq 1 ]; then
             Display --indent 2 --text "- Checking status DHCP client" --result "${STATUS_RUNNING}" --color WHITE
             DHCP_CLIENT_RUNNING=1