fix(onboarding): re-add warning when trying to re-import same key

Possible a fix for #5529

ui/app/AppLayouts/Onboarding/views/SeedPhraseInputView.qml

@@ -1,5 +1,6 @@
 import QtQuick 2.12
 import QtGraphicalEffects 1.13
+import QtQuick.Dialogs 1.3
 
 import StatusQ.Controls 0.1
 import StatusQ.Popups 0.1
@@ -21,6 +22,28 @@ OnboardingBasePage {
 
     signal seedValidated()
 
+    Connections {
+        target: OnboardingStore.onboardingModuleInst
+        onAccountImportError: {
+            if (error === Constants.existingAccountError) {
+                importSeedError.title = qsTr("Keys for this account already exist")
+                importSeedError.text = qsTr("Keys for this account already exist and can't be added again. If you've lost your password, passcode or Keycard, uninstall the app, reinstall and access your keys by entering your seed phrase")
+            } else {
+                importSeedError.title = qsTr("Error importing seed")
+                importSeedError.text = error
+            }
+            importSeedError.open()
+        }
+        onAccountImportSuccess: {
+            root.seedValidated()
+        }
+    }
+    MessageDialog {
+        id: importSeedError
+        icon: StandardIcon.Critical
+        standardButtons: StandardButton.Ok
+    }
+
     Item {
         implicitWidth: 731
         implicitHeight: 472
@@ -202,7 +225,6 @@ OnboardingBasePage {
                     }
                     if (Utils.isMnemonic(root.mnemonicString) && !OnboardingStore.validateMnemonic(root.mnemonicString)) {
                         OnboardingStore.importMnemonic(root.mnemonicString)
-                        root.seedValidated();
                         root.mnemonicString = "";
                         root.mnemonicInput = [];
                     } else {