number.py in python-crypto requires libgmp >=5 to avoid PowmInsecureWarning in RHEL6

Issue

• Getting a python warning that suggests number.py from the python-crypto library requires libgmp >=5 when the libgmp version available in RHEL6 is verion 4:

/usr/lib64/python2.6/site-packages/Crypto/Util/number.py:57:
PowmInsecureWarning: Not using mpz_powm_sec.  You should rebuild using libgmp
>= 5 to avoid timing attack vulnerability.
  _warn("Not using mpz_powm_sec.  You should rebuild using libgmp >= 5 to avoid timing attack vulnerability.", PowmInsecureWarning).