Hana : pyhdb is deprecated, upgrade to the hdbcli package

[piotch]

We have done this upgrade #430

But we rolled it back :

1. the hdbcli lib is writing traces in a file and we would like to avoir this, there seem to be a way to control tracing : https://help.sap.com/viewer/f1b440ded6144a54ada97ff95dac7adf/2.8/en-US/57e04b844d9f40d0bd5ca90f72629255.html but we did not manage to uses these to not write the trace

2. we are not sure if the hdbcli licence allows us to build a connector in a repo with our type of licence