fix: user error code to detect system error
fix: user error code to detect system error

As system error numbers vary across the systems, error code is used to detect
a specific error.

Fix #155

tomateos/S3,tomateos/S3,lucisilv/Silviu_S3-Antidote,scality/S3,lucisilv/Silviu_S3-Antidote,lucisilv/Silviu_S3-Antidote,lucisilv/Silviu_S3-Antidote,lucisilv/Silviu_S3-Antidote,scality/S3,truststamp/S3,truststamp/S3,truststamp/S3,scality/S3,scality/S3,tomateos/S3,truststamp/S3,tomateos/S3,lucisilv/Silviu_S3-Antidote,truststamp/S3,tomateos/S3,scality/S3,tomateos/S3,truststamp/S3,scality/S3,tomateos/S3,tomateos/S3,scality/S3,scality/S3,truststamp/S3,truststamp/S3,lucisilv/Silviu_S3-Antidote,lucisilv/Silviu_S3-Antidote