SSL: fixed unexpected certificate requests (ticket #2008). Using SSL_CTX_set_verify(SSL_VERIFY_PEER) implies that OpenSSL will send a certificate request during an SSL handshake, leading to unexpected certificate requests from browsers as long as there are any client certificates installed. Given that ngx_ssl_trusted_certificate() is called unconditionally by the ngx_http_ssl_module, this affected all HTTPS servers. Broken by 699f6e55bbb4 (not released yet). Fix is to set verify callback in the ngx_ssl_trusted_certificate() function without changing the verify mode.