Bug #1549, 1726 --> be sure to clear the prefs for the bogus identity we create during migration. This was causing

problems on the commercial build. (Landing from beta2 branch to tip)
r=alecf

mailnews/base/src/nsMessengerMigrator.cpp

@@ -665,6 +665,7 @@ nsMessengerMigrator::UpgradePrefs()
     if (NS_FAILED(rv)) return rv;
 
 	// remove the temporary identity we used for migration purposes
+    identity->ClearAllValues();
     rv = accountManager->RemoveIdentity(identity);
     return rv;
 }