Proxy: detection of data after final chunk. Previously, additional data after final chunk was either ignored (in the same buffer, or during unbuffered proxying) or sent to the client (in the next buffer already if it was already read from the socket). Now additional data are properly detected and ignored in all cases. Additionally, a warning is now logged and keepalive is disabled in the connection.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


have=NGX_SUPPRESS_WARN . auto/have

have=NGX_SMP . auto/have