lib-http: http-client: Prevented http_client_request_continue_payload() from segfaulting when the callback sets the request pointer to NULL.
lib-http: http-client: Prevented http_client_request_continue_payload() from segfaulting when the callback sets the request pointer to NULL.

LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot