Deal with the case were the sensor is new (no previous calibration matrix) and lambda diff from 0

[fjandrad]

When a sensor is new it has no previous calibration matrix we should not do any regularization. The code at the moment always does regularization so a fix is to set lambda to 0 so that regularization has no effect in the least squares. Therefore we should verify is a first time sensor before we attempt to estimate the matrices and not after.