Issue #2706 - Resource Service Incorrectly Returning 404

Removed response.flushBuffer() after writing to fix DefaultServletTest.testFiltered()

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-server/src/main/java/org/eclipse/jetty/server/ResourceService.java

@@ -688,8 +688,6 @@ public class ResourceService
                     BufferUtil.writeTo(buffer,out);
                 else
                     content.getResource().writeTo(out,0,content_length);
-
-                response.flushBuffer();
             }
             // else do a bypass write
             else