feat(searchbar): tweak placeholder colors

Author: nolimits4web

src/core/components/searchbar/searchbar-vars.less

@@ -42,10 +42,10 @@
     --f7-searchbar-input-bg-color: #e4e4e4;
   });
   .dark-vars({
+    --f7-searchbar-placeholder-color: rgba(255, 255, 255, 0.4);
     --f7-searchbar-input-text-color: #fff;
     --f7-searchbar-search-icon-color: rgba(255, 255, 255, 0.4);
     --f7-searchbar-input-bg-color: #2a2a2a;
-    --f7-searchbar-placeholder-color: rgba(255, 255, 255, 0.4);
   });
 });
 .md-vars({