On Windows, CPU plugin is not displayed correctly (on both TUI and WebUI)

[nicolargo]

On Windows OS (Windows 10), CPU plugin is not displayed correctly.

"dpc" is displayed but without any value.

Value is available in the status:

cpu: {'total': 16.3, 'user': 14.5, 'system': 1.7, 'idle': 83.7, 'dpc': 0.0, 'ctx_switches': 4661, 'interrupts': 5667, 'soft_interrupts': 0, 'syscalls': 15752, 'cpucore': 4, 'time_since_update': 2.0128655433654785, 'ctx_switches_gauge': 106214098, 'ctx_switches_rate_per_sec': 2315.0, 'interrupts_gauge': 88439490, 'interrupts_rate_per_sec': 2815.0, 'soft_interrupts_gauge': 0, 'syscalls_gauge': 506987676, 'syscalls_rate_per_sec': 7825.0}

[nicolargo]

To be tested from the dev branch.