Tests: added delay before SIGQUIT in access_log partial tests.
Tests: added delay before SIGQUIT in access_log partial tests.

This change is necessary to avoid race between
client connection close and Unit close.

Also "read_timeout" value decreased to speed up tests.

nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit