inform user if account not exists

Signed-off-by: alperozturk96 <alper_ozturk@proton.me>

Author: alperozturk96

app/src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.kt

@@ -3081,16 +3081,14 @@ class FileDisplayActivity :
             intent,
             object : AccountReceiverCallback {
                 override fun onAccountReceived(accountName: String) {
-                    val user = accountManager.getUser(accountName)
-                    if (user.isEmpty) {
-                        Log_OC.e(TAG, "user is not present")
-                        DisplayUtils.showSnackMessage(this@FileDisplayActivity, R.string.account_not_found)
-                        return
-                    }
+                    val account = accountManager.getUser(accountName).orElse(null)
+                        ?: run {
+                            Log_OC.w(TAG, "user is not present")
+                            DisplayUtils.showSnackMessage(this@FileDisplayActivity, R.string.account_not_found)
+                            return
+                        }
 
-                    if (user.isPresent) {
-                        accountClicked(user.get())
-                    }
+                    accountClicked(account)
                 }
 
                 override fun onAccountError(reason: String) {