bug: Illegal sweep settings

[Shaeto]

Bug Report

NanoVNA-Saver version:

0.6.1 under Ubuntu 22.04.2 LTS x64

Current behavior:

Application crashes on any change in the sweep settings fields with trace:
Traceback (most recent call last):
File "NanoVNASaver/Controls/SweepControl.py", line 216, in update_step_size
File "NanoVNASaver/Controls/SweepControl.py", line 219, in update_sweep
File "NanoVNASaver/Settings/Sweep.py", line 119, in update
File "NanoVNASaver/Settings/Sweep.py", line 145, in check
ValueError: Illegal sweep settings: Sweep(14000000, 137800, 101, 1, Properties(name='', mode=<SweepMode.SINGLE: 0>, averages=(3, 0), logarithmic=False))
Aborted (core dumped)

Expected behavior:

Application is allows to change and apply sweep settings

Steps to reproduce:

Start application, connect to VNA (NanoVNA V2 Plus4 firmware 20220814), try to change default 200M-300M range to 1M-100M