Remove useless imports.

Change-Id: Ibaadf96e9480fc8d294497322ec2a6c10b7c2c30
Propagate the modification of the logger verbosity on the console handler.

In order to see debug messages, the verbosity of the logger and of its attached
handler must be edited.

Change-Id: I2c9d528a284129177440856c5bb7caf37d117f8a