Incerase client_body_buffer_size to reduce nginx warnings

[glensc]

nginx emits these warnings to logs:

 web_1    | 2020-07-11T12:44:05.894779100Z 2020/07/11 12:44:05 [warn] 20#20: *189 a client request body is buffered to a temporary file /var/cache/nginx/client_temp/0000000055, client: 172.23.0.1, server: , request: "POST /run/import?token=token HTTP/1.1", host: "localhost:8142"

Just to get rid of the warning, increase the buffer to 1M. My typical payloads are around 512k.

ref:

• https://serverfault.com/questions/511789/nginx-client-request-body-is-buffered-to-a-temporary-file

[markstory]

Looks good to me.