protocol field in security group rule is lower case of imcp, icmpv6, tcp and udp

protocol field in security group rule is lower case of imcp, icmpv6, tcp and udp
This is defined in neutron/extension/securitygroup.py

The following is the packet capture.
POST /controller/nb/v2/neutron/security-group-rules HTTP/1.1
Host: 143.183.96.62:8087
Content-Length: 397
Accept-Encoding: gzip, deflate
Accept: /
User-Agent: python-requests/2.7.0 CPython/2.7.6 Linux/3.13.0-63-generic
Connection: keep-alive
Content-Type: application/json
Authorization: Basic YWRtaW46YWRtaW4=

{
"security_group_rule":

{ "remote_group_id": null, "direction": "ingress", "remote_ip_prefix": null, "protocol": "tcp", "ethertype": "IPv4", "tenant_id": "6f25fa70b0e547d8aab2f68ea4c138fd", "port_range_max": 81, "port_range_min": 80, "id": "1fbe4810-e2a6-4d8a-ab0d-553dc5345a44", "security_group_id": "919bb6ed-2929-4d6e-b269-b321d59fe499" }

}