Fix input height border

Created by: iamandrewluca

When changing $input-border-width, $input-height-border does not change and select.form-control custom-select custom-file will still have $input-height which is resolved from $input-btn-border-width

This will work in cases when want controls with border, and buttons without.

Temporary fix will be to override 2 variables

$input-border-width: 2px !default;

// which is
// $input-height-border: $input-btn-border-width * 2 !default;
$input-height-border: $input-border-width * 2 !default;