Dav: fixed segfault on PUT if body was already read (ticket #238). If request body reading happens with different options it's possible that there will be no r->request_body->temp_file available (or even no r->request_body available if body was discarded). Return internal server error in this case instead of committing suicide by dereferencing a null pointer.

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


have=NGX_SUPPRESS_WARN . auto/have

have=NGX_SMP . auto/have