Bug 1315662 - delete SMTP server login credentials when deleting the account or if hostname/username changes.

Tag #1273

mailnews/base/prefs/content/am-smtp.js

@@ -54,6 +54,11 @@ var gSmtpServerListWindow =
 
       if (!cancel)
       {
+      // Remove password information first.
+      try {
+        server.forgetPassword();
+      } catch (e) { /* It is OK if this fails. */ }
+      // Remove the server.
         MailServices.smtp.deleteServer(server);
         parent.replaceWithDefaultSmtpServer(server.key);
         this.refreshServerList("", true);