AWS Lambda -> sqs.receiveMessage Warning: Ignoring extra certs

I'm getting the following error on AWS lambda when trying to do a sqs.receiveMessage - is anyone else getting this or am i going loco?

2018-03-29T15:55:41.776Z 9aa0011b-3369-11e8-8b07-77caca8abbe8 (node:1) Warning: Ignoring extra certs from /etc/pki/tls/certs/ca-bundle.crt, load failed: error:0B07C065:x509 certificate routines:X509_STORE_add_cert:cert already in hash table

i've tried:

• renaming the lambda function to something else
• reverting my code back to previous known working state
• googling the error (and no results)

has anybody got ideas / similar problems?