$range-header-background-color problem

[bjmac]

I'm setting the sass variable $range-header-background-color in Scheduler 2.1.1, but it's having no effect.

I noticed that in variables.scss, the '!default' flag is not set for this variable, which I think is causing this problem. It's also not set for $eventdragselect-border.

[pmiklashevich]

Thank you for the report! Fixed in the next nightlies and release!