XmlCatalog had become broken with any dtd/entity location that was not a file.

PR: 35269


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@278412 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/types/XMLCatalog.java

@@ -670,7 +670,7 @@ public class XMLCatalog extends DataType
             }
         }
 
-        if (url != null) {
+        if (url != null && url.getProtocol().equals("file")) {
             String fileName = FILE_UTILS.fromURI(url.toString());
             if (fileName != null) {
                 log("fileName " + fileName, Project.MSG_DEBUG);