Follow the specification.

PUT to shacache shall be done to shacache path, not shacache path+sha sum.

This break backward compatibility during upload, but download is used more
often.

slapos/libnetworkcache.py

@@ -97,13 +97,12 @@ class NetworkcacheClient(object):
         break
       sha512sum.update(d)
     sha512sum = sha512sum.hexdigest()
-    path = os.path.join(self.shacache_path, sha512sum)
 
     file_descriptor.seek(0)
     shacache_connection = httplib.HTTPConnection(self.shacache_host,
       self.shacache_port)
     try:
-      shacache_connection.request('PUT', path, file_descriptor,
+      shacache_connection.request('PUT', self.shacache_path, file_descriptor,
                                                  self.shacache_header_dict)
       result = shacache_connection.getresponse()
       data = result.read()