Fix console set interface IP address

Problem as per forum https://forum.pfsense.org/index.php?topic=83651.0
The problem comes whenever services_dhcpd_configure is called - the global $config gets reset from the actual current config, and any pending changes in the current process are lost.
It was introduced by commit 86ce2df
in which services_dhcpdv4_configure() does:

require_once('pkg-utils.inc')

and pkg-utils.inc does various stuff like:

if(file_exists("/cf/conf/use_xmlreader"))
require_once("xmlreader.inc");
else
require_once("xmlparse.inc");

which seems to cause a reset of the $config variable, thus losing the pending changes the user has entered at the console.

The top-level code in rc.initial.setlanip really does not need to (and should not) implement any changes along the way - it should collect all the answers from the user, then write_config and then make all the necessary calls to routines to implement the changes on the running system. This fixes it - defer any calls to services_dhcpd_configure() until after all questions are answered and write_config has happened.

src/etc/rc.initial.setlanip

@@ -396,14 +396,12 @@ function console_configure_dhcpd($version = 4) {
 	} else {
 		/* TODO - this line is causing a "Fatal error: Cannot unset
 		   string offsets in rc.initial.setlanip" on below line
-		   number */
-		if($config[$dhcpd][$interface])
+		   number - Nov 2014 - is it really? */
+		if($config[$dhcpd][$interface]) {
 			unset($config[$dhcpd][$interface]['enable']);
-		echo "Disabling DHCPD...";
-		if (!$dry_run) {
-			services_dhcpd_configure();
+			printf(gettext("Disabling %s DHCPD..."), $label_IPvX);
+			$restart_dhcpd = true;
 		}
-		echo "Done!\n";
 	}
 }
 
@@ -453,7 +451,7 @@ if(!$config['interfaces']['lan']) {
 	unset($config['nat']);
 	if (!$dry_run) {
 		system("rm /var/dhcpd/var/db/* >/dev/null 2>/dev/null");
-		services_dhcpd_configure();
+		$restart_dhcpd = true;
 	}
 }