DEV: re-enable test skipped in 7dce4bfd

Leak in lib:sharing tests was the likely cause of failure.

test/javascripts/acceptance/topic-quote-button-test.js

@@ -81,7 +81,7 @@ QUnit.test(
   }
 );
 
-QUnit.skip(
+QUnit.test(
   "Shows single share button when site setting only has one item",
   async function(assert) {
     this.siteSettings.share_quote_buttons = "twitter";

test/javascripts/lib/sharing-test.js

@@ -3,6 +3,9 @@ import Sharing from "discourse/lib/sharing";
 QUnit.module("lib:sharing", {
   beforeEach() {
     Sharing._reset();
+  },
+  afterEach() {
+    Sharing._reset();
   }
 });