Update sponsor page UI

Author: zxdong262

src/views/parts/sponsor.pug

@@ -13,7 +13,3 @@ a(href='https://opencollective.com/electerm', rel='noreferrer') https://opencoll
 h2 微信赞赏码
 
 img(src='https://electerm.html5beta.com/electerm-wechat-donate.png')
-
-h2 微信群
-
-img(src='https://electerm.html5beta.com/electerm-wechat-group-qr.jpg')