Implement the GnuTLS version of mailstream_low_ssl_get_certificate_chain()
Implement the GnuTLS version of mailstream_low_ssl_get_certificate_chain()

disaykin/libetpan,disaykin/libetpan,tipbit/libetpan,disaykin/libetpan,jjz/libetpan,tipbit/libetpan,tipbit/libetpan,jjz/libetpan,jjz/libetpan