replacing slider precision harcoded value

[Guillaume-Fgt]

#409

Following your answer @jagenjo , here is the PR. Thank you for your quick answer.

[jagenjo]

instead of w.options.precision !== undefined
please use != null, as in your condition null would be a valid value.

[Guillaume-Fgt]

For the combo case, the value is also checked using undefined. Do you want me to change this one too?

[jagenjo]

no need, but you did the fix wrong, !== null means undefined is a valid value, just != null controls undefined and null as possible conditions.

[Guillaume-Fgt]

thank you for you patience, I am not comfortable with JavaScript, still a lot to learn...

[jagenjo]

Thanks to you.