Fix a bug on Retry.read. It should have the same arguments as httplib.HTTPResponse.read.

slapos/libnetworkcache.py

@@ -142,13 +142,13 @@ class Retry(object):
     finally:
       connection.close()
 
-  def read(self, size=16*1024):
-    data = self.response.read(size)
+  def read(self, amt=None):
+    data = self.response.read(amt)
     if not data:
       if self.position < self.content_length:
         self.getresponse()
         if self.response is not None:
-          data = self.response.read(size)
+          data = self.response.read(amt)
     self.position += len(data)
     return data