_stacked.scss in font-awesome-sass-5.5.0

- old
+ new

@@ -5,10 +5,10 @@
   display: inline-block;
   height: 2em;
   line-height: 2em;
   position: relative;
   vertical-align: middle;
-  width: 2em;
+  width: ($fa-fw-width*2);
 }
 
 .#{$fa-css-prefix}-stack-1x,
 .#{$fa-css-prefix}-stack-2x {
   left: 0;