SSL: clear error queue after OPENSSL_init_ssl(). The function may leave error in the error queue while returning success, e.g., when taking a DSO reference to itself as of OpenSSL 1.1.0d: https://git.openssl.org/?p=openssl.git;a=commit;h=4af9f7f Notably, this fixes alert seen with statically linked OpenSSL on some platforms. While here, check OPENSSL_init_ssl() return value.

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


cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  0
#endif

END