[BUG] Crash when connecting/disconnecting power adapter

Describe the bug

When running bpytop on Debian Testing and with the battery-mode enabled, bpytop crashes when I connect or disconnect my power adapter.

Info (please complete the following information):

• bpytop version: 1.0.27
• psutil version: 5.7.2
• (Linux) Linux distribution and version: Debian Testing
• Terminal used: zsh
• Python version: 3.8.5

Additional context

contents of ~/.config/bpytop/error.log

12/09/20 (13:16:48) | INFO: New instance of bpytop version 1.0.27 started with pid 297438
12/09/20 (13:16:48) | INFO: Loglevel set to INFO
12/09/20 (13:17:32) | ERROR: Data collection thread failed with exception: 'NoneType' object has no attribute 'percent'
Traceback (most recent call last):
  File "/usr/local/bin/bpytop", line 2503, in _runner
    collector._draw()
  File "/usr/local/bin/bpytop", line 2705, in _draw
    CpuBox._draw_fg()
  File "/usr/local/bin/bpytop", line 1636, in _draw_fg
    if CONFIG.show_battery and cls.battery_present and psutil.sensors_battery().percent != cls.battery_percent:
AttributeError: 'NoneType' object has no attribute 'percent'
12/09/20 (13:17:33) | WARNING: Exiting with errorcode (1). Runtime 0:00:45

[aristocratos]

Yeah, just noticed from psutil documentation:

secsleft: a rough approximation of how many seconds are left before the battery runs out of power. If the AC power cable is connected this is set to psutil.POWER_TIME_UNLIMITED. If it can’t be determined it is set to psutil.POWER_TIME_UNKNOWN.

Will add a check to hide if the value is negative.

[aristocratos]

@delta-one Fixed in v1.0.30 Hopefully last fix for this 😃