é um problema geral para o curl compilado com o NSS (somente os pacotes redhat-linuxes, debian e suse curl compilados sem o nss). você precisa compilar o curl de fontes sem nss-library.
Então, eu não tenho solução como https-connections trabalhou com o nss-curl.
curl --version curl 7.29.0 (x86_64-redhat-linux-gnu) libcurl/7.29.0 NSS/3.14.3.0 zlib/1.2.7 libidn/1.26 libssh2/1.4.3 Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smtp smtps telnet tftp Features: AsynchDNS GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz
curl --version curl 7.25.0 (x86_64-suse-linux-gnu) libcurl/7.25.0 OpenSSL/1.0.1e zlib/1.2.7 libidn/1.25 libssh2/1.4.0 Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smtp smtps telnet tftp Features: AsynchDNS GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP