app-sidebar-nav-label.component sets an incomplete variant style

[coyoteecd]

I think there's a small bug in app-sidebar-nav-label.component.ts, at this line:

    const variant = `text-${this.item.label.variant}`;
    classes[variant] = !!variant;

There, !!variant will always evaluate to true, because of the interpolated string. Consequence is that a dummy text- class will be added to the label items. Small bug, but easy to fix.