Avoid DhcpServer Perl module to overlap with Yast2::SystemService

Despite services will be managed by Yast2::SystemService from now on, it
is necessary to keep the related Perl code for `auto` and `config` modes
until  them will be also managed from Ruby.

src/modules/DhcpServer.pm

@@ -1745,32 +1745,34 @@ sub Write {
     SCR->Write (".sysconfig.dhcpd.DHCPD_INTERFACE", $ifaces_list);
     SCR->Write (".sysconfig.dhcpd.DHCPD_OTHER_ARGS", $other_options);
     SCR->Write (".sysconfig.dhcpd", undef);
-
 
-    if ($start_service)
-    {
-	y2milestone ("Enabling the DHCP service");
-	my $ret = 1;
-	if (! $write_only)
-	{
-	    $ret = Service->Restart ($SERVICE);
-	}
-	Service->Enable ($SERVICE);
-	if (!$ret)
-	{
-	    # error report
-	    Report->Error (__("Error occurred while restarting the DHCP daemon."));
-	    $ok = 0;
-	}
-    }
-    else
-    {
-	y2milestone ("Disabling the DHCP service");
-	if (! $write_only)
-	{
-	    Service->Stop ($SERVICE);
-	}
-	Service->Disable ($SERVICE);
+    if (Mode->auto() || Mode->config())
+    {
+        if ($start_service)
+        {
+        y2milestone ("Enabling the DHCP service");
+        my $ret = 1;
+        if (! $write_only)
+        {
+            $ret = Service->Restart ($SERVICE);
+        }
+        Service->Enable ($SERVICE);
+        if (!$ret)
+        {
+            # error report
+            Report->Error (__("Error occurred while restarting the DHCP daemon."));
+            $ok = 0;
+        }
+        }
+        else
+        {
+        y2milestone ("Disabling the DHCP service");
+        if (! $write_only)
+        {
+            Service->Stop ($SERVICE);
+        }
+        Service->Disable ($SERVICE);
+        }
     }
 
     Progress->NextStage ();