re-instate filters button padding

opentech/static_src/src/sass/apply/components/_button.scss

@@ -71,6 +71,7 @@
         display: flex;
         justify-content: space-between;
         max-width: 300px;
+        padding: 15px 20px;
         font-weight: $weight--normal;
         color: $color--default;
         background: url('./../../images/filters.svg') $color--white no-repeat 93% center;