Docs for B319 listed twice
Docs for B319 listed twice

The blacklist calls doc lists B319 twice. This patch removes the
duplicate.

[1]: https://docs.openstack.org/developer/bandit/blacklists/blacklist_calls.html#b313-b320-xml

Change-Id: I94ca7cb1201f6d74ce8672294d2ba421ea5a608c

stackforge/bandit,stackforge/bandit,pombredanne/bandit,pombredanne/bandit,chair6/bandit