form-control-focus mixin error

[Mathiu]

Hi,

I am getting error while using form-control-focus mixin:

Message:
node_modules/bootstrap-sass/assets/stylesheets/bootstrap/mixins/_forms.scss
Error: wrong number of arguments (2 for 1) for `box-shadow'
on line 60 of node_modules/bootstrap-sass/assets/stylesheets/bootstrap/mixins/_forms.scss
>> @include box-shadow(inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px $color-rgba)
-------------^

I didn't find any similar issue and not sure how do I create a test case for this.

I made a pull request with a fix (#1140)

---

node-sass 4.5.3 (Wrapper) [JavaScript]
libsass 3.5.0.beta.2 (Sass Compiler) [C/C++]
Node.JS v8.4.0