[hotfix] use DiskFileItemFactor default threshhold

Setting the SizeThreshhold to a low value can lead to
Unexpected EOF errors when decoding  multipart messages.

Author: line-o

exist-core/src/main/java/org/exist/http/servlets/HttpRequestWrapper.java

@@ -186,9 +186,6 @@ private void parseMultipartContent() {
         // Create a factory for disk-based file items
         final DiskFileItemFactory factory = new DiskFileItemFactory();
 
-        // Dizzzz: Wonder why this should be zero
-        factory.setSizeThreshold(0);
-
         // Create a new file upload handler
         final ServletFileUpload upload = new ServletFileUpload(factory);