xend: adjust relocation buffer size

This can greatly improve ssl relocation performance (to about 1/3
compared with buffersize 1024).

Signed-off-by: Zhigang Wang <zhigang.x.wang@oracle.com>

tools/python/xen/web/connection.py

@@ -37,7 +37,7 @@ specifying what kind of socket they are. There are subclasses
 for TCP and unix-domain sockets (see tcp.py and unix.py).
 """
 
-BUFFER_SIZE = 1024
+BUFFER_SIZE = 16384
 BACKLOG = 5