curl 7.38 bug fix for godaddy ca with openssl

When curl is built with brewed openssl, requests to any
https urls that use a cert issued by GoDaddy fail with
a `curl (60) SSL certificate problem`. Explicitly
specifying brewed openssl's cert bundle resolves this
issue.

Test case:

    $ brew install --with-openssl curl

    $ /usr/local/Cellar/curl/7.38.0/bin/curl -v https://www.godaddy.com/
    * Hostname was NOT found in DNS cache
    *   Trying 23.220.221.130...
    * Connected to www.godaddy.com (23.220.221.130) port 443 (#0)
    * successfully set certificate verify locations:
    *   CAfile: none
      CApath: /usr/local/etc/openssl
    * SSLv3, TLS handshake, Client hello (1):
    * SSLv3, TLS handshake, Server hello (2):
    * SSLv3, TLS handshake, CERT (11):
    * SSLv3, TLS alert, Server hello (2):
    * SSL certificate problem: self signed certificate in certificate chain
    * Closing connection 0
     curl: (60) SSL certificate problem: self signed certificate in certificate chain
    More details here: http://curl.haxx.se/docs/sslcerts.html

    curl performs SSL certificate verification by default, using a "bundle"
     of Certificate Authority (CA) public keys (CA certs). If the default
     bundle file isn't adequate, you can specify an alternate file
     using the --cacert option.
    If this HTTPS server uses a certificate signed by a CA represented in
     the bundle, the certificate verification probably failed due to a
     problem with the certificate (it might be expired, or the name might
     not match the domain name in the URL).
    If you'd like to turn off curl's verification of the certificate, use
     the -k (or --insecure) option.