Fix a crash bringing up settings

Change-Id: If29fc7a4113ed7245cd82e6b26c63f08f4b9db2d
diff --git a/src/com/android/email/activity/setup/AccountSettings.java b/src/com/android/email/activity/setup/AccountSettings.java
index 00e4386..0a6e283 100644
--- a/src/com/android/email/activity/setup/AccountSettings.java
+++ b/src/com/android/email/activity/setup/AccountSettings.java
@@ -344,6 +344,7 @@
         // We need to make sure that a fragment about to be attached is valid. This corrects
         // a security vulnerability.
         return (TextUtils.equals(AccountSettingsFragment.class.getName(), fragmentName) ||
+                TextUtils.equals(GeneralPreferences.class.getName(), fragmentName) ||
                 super.isValidFragment(fragmentName));
     }