不要なplatinum_sponsorsの宣言を削除

Author: Fukusan64

_includes/top/sections/sponsor.html

@@ -1,4 +1,3 @@
-{% assign platinum_sponsors   = site.data.sponsors | where: "type", "platinum"   %}
 {% assign gold_sponsors       = site.data.sponsors | where: "type", "gold"       %}
 {% assign silver_sponsors     = site.data.sponsors | where: "type", "silver"     %}
 {% assign bronze_sponsors     = site.data.sponsors | where: "type", "bronze"     %}