libgcrypt11 - security update

Multiple vulnerabilities were discovered in libgcrypt:

• CVE-2014-3591
  The Elgamal decryption routine was susceptible to a side-channel
  attack discovered by researchers of Tel Aviv University. Ciphertext
  blinding was enabled to counteract it. Note that this may have a
  quite noticeable impact on Elgamal decryption performance.
• CVE-2015-0837
  The modular exponentiation routine mpi_powm() was susceptible to a
  side-channel attack caused by data-dependent timing variations when
  accessing its internal pre-computed table.