added 75px spacing variable and applied

Author: jeppekroghitk

src/stories/Library/Modals/modal-loan/modal-loan.scss

@@ -37,7 +37,7 @@ $MODAL_LOAN_CONTAINER_WIDTH: 1000px;
 }
 
 .modal-loan__list-materials--bottom-buttons-visible {
-  padding-bottom: 75px;
+  padding-bottom: #{$s-75}px;
 }
 
 .modal-loan__buttons {

src/stories/Library/spacing/spacing.scss

@@ -7,6 +7,7 @@ $s-32: 32;
 $s-35: 35;
 $s-48: 48;
 $s-64: 64;
+$s-75: 75;
 $s-80: 80;
 $s-96: 96;
 $s-112: 112;