Re-opened this bug: I am not sure the fix did anything.
I applied the fix and still see the exact same thing in the neutron logs, e.g.:


2017-11-13 09:55:49,914.914 10778 INFO neutron.wsgi [req-4c18bd00-48c2-498f-92ee-824e215b83b9 c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:49] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.062934
2017-11-13 09:55:49,982.982 10778 INFO neutron.wsgi [req-f69f7d30-6121-456e-8dec-4c142965e91c c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:49] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.055435
2017-11-13 09:55:50,054.054 10778 INFO neutron.wsgi [req-4a389783-31b1-421e-a0f9-b31e419bc5df c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.058556
2017-11-13 09:55:50,119.119 10778 INFO neutron.wsgi [req-3dffc0a6-5f14-400f-8b4c-02555d2e262d c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.052321
2017-11-13 09:55:50,198.198 10778 INFO neutron.wsgi [req-007398bc-72e9-4858-8b04-f49face2304d c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.066602
2017-11-13 09:55:50,270.270 10778 INFO neutron.wsgi [req-092f3234-926b-4f2c-8626-1b3e7f1203dd c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.059341
2017-11-13 09:55:50,334.334 10778 INFO neutron.wsgi [req-20f45327-9d24-482c-b648-176e85d46a81 c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.051137
2017-11-13 09:55:50,397.397 10778 INFO neutron.wsgi [req-0fa86b48-59a0-460c-829e-ea008a442ed0 c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.050534
2017-11-13 09:55:50,459.459 10778 INFO neutron.wsgi [req-8bb7bfdc-b12a-46b3-a76d-7ba299d45a84 c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.048582
2017-11-13 09:55:50,527.527 10778 INFO neutron.wsgi [req-f19d8910-967c-4236-91d3-a59852482383 c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.054999
2017-11-13 09:55:50,596.596 10778 INFO neutron.wsgi [req-f21e1335-ddd7-49b0-9f2b-da9d37e48c8b c70f3fc161e04718a108cf8192d0816e d2930aef1c824f048b8e1301b3ded161 - - -] 10.41.0.33 - - [13/Nov/2017 09:55:50] "GET /v2.0/security-groups/d2770f7f-8695-48de-806b-e690189e25a8 HTTP/1.1" 200 41170 0.056300