Delete confirmation button in UI for MSA-AAD registration (#6586)

Author: zhhyu

src/NuGetGallery/Views/Users/Thanks.cshtml

@@ -14,7 +14,10 @@
         <div class="@ViewHelpers.GetColumnClasses(ViewBag)">
             <p class="ms-fontSize-xl">Welcome @CurrentUser.Username! Now that you have a NuGet.org account, let's get you started!</p>
 
-            <p>Make sure your email is verified. <a href="@Url.ConfirmationRequired()">Confirm your account</a></p>
+            @if (!CurrentUser.Confirmed)
+            {
+                <p>Make sure your email is verified. <a href="@Url.ConfirmationRequired()">Confirm your account</a></p>
+            }
 
             <p>Want to update your account? <a href="@Url.AccountSettings()">View Account Settings</a></p>