Improvements and fixes on logging

[bugrasan]

Since we get the module specific logger with logging.getLogger(__name__) we should use that one.

[tickzip]

When I tested this, I found an unintended side effect where the PR now causes asyncio's debug messages to appear in the terminal:

tickzip@guix ~> onlykey-cli
OnlyKey CLI v1.2.10
Control-D to exit.


DEBUG:asyncio:Using selector: EpollSelector
OnlyKey>

I managed to narrow it down to this line as the cause, but I can't think why it triggers these debug messages.

log.debug('connected')

I was also able to suppress the messages using

logging.getLogger('asyncio').setLevel(logging.WARNING)