Add comment.

briar-android/src/main/java/org/briarproject/briar/android/login/PasswordActivity.java

@@ -56,7 +56,8 @@ public class PasswordActivity extends BaseActivity {
 		overridePendingTransition(R.anim.fade_in, R.anim.fade_out);
 
 		if (!accountManager.accountExists()) {
-			// TODO: Finish instead of deleting account?
+			// This can happen on older devices if the app is relaunched from
+			// recent apps after clearing data
 			deleteAccount();
 			return;
 		}