removing whitespace from css files

apps/openassessment/xblock/static/sass/xb/elements/_controls.scss

@@ -117,7 +117,6 @@
     background: $action-primary-color-active;
     border-color: $action-primary-color-active;
 
-
     &:hover, &:active, &:focus {
 
     }

apps/openassessment/xblock/static/sass/xb/elements/_typography.scss

@@ -193,7 +193,6 @@
   font-style: normal;
 }
 
-
 %emphasis-alpha {
   @extend %emphasis;
   @extend %t-weight3;