Bug 1918630 - Follow up to rev 1c9ec34994a2, fix incorrect import which causes bustage. rs=bustage-fix

Differential Revision: https://phabricator.services.mozilla.com/D222206

--HG--
extra : amend_source : 912f8c80db2472491f7d28557060f019cd5bdd85

mail/test/browser/shared-modules/ContentTabHelpers.sys.mjs

@@ -8,7 +8,7 @@ import * as wh from "resource://testing-common/mail/WindowHelpers.sys.mjs";
 
 import { Assert } from "resource://testing-common/Assert.sys.mjs";
 import { TestUtils } from "resource://testing-common/TestUtils.sys.mjs";
-import { EventUtils } from "resource://testing-common/EventUtils.sys.mjs";
+import * as EventUtils from "resource://testing-common/mail/EventUtils.sys.mjs";
 
 var FAST_TIMEOUT = 1000;
 var FAST_INTERVAL = 100;