speed up emoji picker somewhat

src/modules/instance.js

@@ -374,6 +374,8 @@ const instance = {
             // should have been "pack" field, that would be more useful
           }).sort(byPackThenByName)
           commit('setInstanceOption', { name: 'customEmoji', value: emoji })
+          state.standardEmojiGroupList = null
+          state.standardEmojiList = null
         } else {
           throw (res)
         }