fixed icon color variable name

Author: Karlasa

app/design/frontend/Magento/blank/Magento_CatalogSearch/web/css/source/_module.less

@@ -36,9 +36,9 @@
             @_icon-font-content: @icon-search,
             @_icon-font-size: 35px,
             @_icon-font-line-height: 33px,
-            @_icon-font-color: @minicart-icons-color,
-            @_icon-font-color-hover: @minicart-icons-color-hover,
-            @_icon-font-color-active: @minicart-icons-color-hover,
+            @_icon-font-color: @header-icons-color,
+            @_icon-font-color-hover: @header-icons-color-hover,
+            @_icon-font-color-active: @header-icons-color-hover,
             @_icon-font-text-hide: true
             );
             display: inline-block;