Crash with Minimum density

[yohann-chemtob]

Describe the bug In the separation module, for the minimum density parameter, when trying to enter a value like 0.5, trackR crash at "0."

To Reproduce Enter 0. as a minimum density value and enjoy

Expected behavior Not to crash or a error message in the app if the value is not recognise

Computer (please complete the following information):

• Operating system: Windows 10

R (please complete the following information):

• R version: 4.1.3
• Rvision version: 0.6.0
• shiny version: 1.7.1