Add an extra check for a manual config change that breaks the index

apache/lang/en

@@ -161,6 +161,7 @@ manual_efile=Invalid Apache config file
 manual_etest=Configuration file error detected : $1
 manual_editfile=Edit config file:
 manual_switch=Edit
+manual_evirt=Virtual host could not be found after manual changes - maybe the ServerName was changed?
 
 dir_title=Per-Directory Options
 dir_proxyall=All proxy requests

apache/manual_save.cgi

@@ -73,6 +73,14 @@ if ($config{'test_manual'}) {
 		&error(&text('manual_etest',
 			     "<pre>".&html_escape($err)."</pre>"));
 		}
+	if (defined($in{'virt'}) && !defined($in{'idx'})) {
+		undef(@get_config_cache);
+		($conf, $v) = &get_virtual_config($in{'virt'});
+		if (!$v) {
+			&copy_source_dest($temp, $file);
+			&error($text{'manual_evirt'});
+			}
+		}
 	}
 unlink($temp);
 &unlock_file($file);