textproc/py-elasticsearch5: Prepare for urllib3 >= 1.25

• Backport a patch from the 7.x branch of upstream repository that fixes a possible runtime issue with urllib3 1.25 [1] since that release verifies SSL certificates by default.
  
  Disabling SSL certificate verification via "verify_certs" in elasticsearch won't work then as expected thus set "cert_reqs=CERT_NONE" explicitly to restore that behavior.

PR: 241875, 229322 [1]
Approved by: maintainer timeout (elastic, 14 days)
MFH: 2019Q4