fix: maintain session verify flag for new sub-resources

[scott-c-h]

The current behaviour on the creation of a sub-resource is that the verify flag is reset to False. The flag should be maintained for all the resources that share a session.

This can be shown in the following snippet:

import pycouchdb

server = pycouchdb.Server(..., verify=True)
assert server.resource.session.verify is True 

db = server.database("db_name")
assert db.resource.session.verify is True  # fails without this fix
assert server.resource.session.verify is True  # even worse: fails without this fix