ERROR DURING SWEEP argument out of range with NanoVNA V2

[ok1vaw]

Describe the bug
A clear and concise description of what the bug is.
when changing number of points this error appears. if you confirm it, nanovna saver continues with those borders OK.
To Reproduce
Steps to reproduce the behavior:

1. set 51 points sweep from 1MHz to 60MHz, make a sweep.
   2.change the 60MHz to 64MHz
2. push sweep again
3. Error appears.
   5.click OK
4. Sweep starts.

Expected behavior
A clear and concise description of what you expected to happen.
This should not happen.
Screenshots
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Desktop (please complete the following information):

• OS: [e.g. iOS] win 10
• Python version: [if applicable]
• NanoVNA-Saver version: [e.g. 0.1.4] 0.3.7
  
  debug for test2.txt

Additional context
Add any other context about the problem here.

[Mike4U]

see #322 at Mike4U. This finally worked for me on NanoVNASaver 0.3.8 pre03 but I think it will make other versions work too.