[master] DHCP4_SERVERID_LOADED and DHCP6_SERVERID_LOADED need server-id too

On my home system I received error when running unit tests like:

Message DHCP4_SERVERID_LOADED server-id /home/reed/opt/bind10/var/b10-dhcp4-serverid has been loaded from file %2
assertion ""Excess logger placeholders still exist in message" == NULL" failed: file "../../../../src/lib/log/log_formatter.cc", line 69, function "void isc::log::checkExcessPlaceholders(std::string*, unsigned int)"

I am using --enable-logger-checks. The build farm also uses that.
I am not sure why this was not seen  on the build farm.

I added the missing value for dhcp4 and dhcp6 and the make check completed.

It had slight review on jabber.

src/bin/dhcp4/dhcp4_srv.cc

@@ -61,6 +61,7 @@ Dhcpv4Srv::Dhcpv4Srv(uint16_t port, const char* dbconfig) {
         string srvid_file = CfgMgr::instance().getDataDir() + "/" + string(SERVER_ID_FILE);
         if (loadServerID(srvid_file)) {
             LOG_DEBUG(dhcp4_logger, DBG_DHCP4_START, DHCP4_SERVERID_LOADED)
+                .arg(srvidToString(getServerID()))
                 .arg(srvid_file);
         } else {
             generateServerID();

src/bin/dhcp6/dhcp6_srv.cc

@@ -78,6 +78,7 @@ Dhcpv6Srv::Dhcpv6Srv(uint16_t port)
         string duid_file = CfgMgr::instance().getDataDir() + "/" + string(SERVER_DUID_FILE);
         if (loadServerID(duid_file)) {
             LOG_DEBUG(dhcp6_logger, DBG_DHCP6_START, DHCP6_SERVERID_LOADED)
+                .arg(duidToString(getServerID()))
                 .arg(duid_file);
         } else {
             generateServerID();