Measurements with "C" (celsius) don't get extracted

[ualex73]

If the measurement has special character(s), it doesn't get extract at all. The "Measurements fields" get incorrectly field in the internal hash.

export INFLUX_PW=none;./influx-backup.py --url http://localhost:8086 --user none --dump --dump-db database --dir /var/tmp/database --measurements "°C"

2018-06-22 10:18:16 UTC
Starting backup of "database" db to "/var/tmp/database" dir

Measurements:
['°C']

Measurement fields:
{'°C': {'temperature': 'float', 'icon_str': 'string', 'current_temperature': 'float', 'operation_mode_str': 'string', 'supported_features': 'float', 'value': 'float', 'mode': 'float', 'min_temp': 'float', 'state': 'string', 'attribution_str': 'string', 'max_temp': 'float', 'friendly_name_str': 'string', 'operation_list_str': 'string'}}

Ignoring °C... 0
Done.