fixed bug in empty values in wfs server qgis

SE/se-lib/Api/WfsQgisServer.php

@@ -163,7 +163,7 @@ if(0){// TODO: get BBOX
 							$featureFldNode->appendChild($geomNode);
 						} else {
 							$featureFldNode->nodeValue = str_replace('&', '&', $item->{$fldName});
-							if (empty($featureFldNode->nodeValue)) {
+							if (empty($featureFldNode->nodeValue) && '0' !== $featureFldNode->nodeValue) {
 								continue;
 							}
 						}