QApplication crash with Igniter dialog and Settings
There is a bug that happens when you run settings and you are missing mongodb credentials in keyring so Igniter dialog will pop-up. After successfully entering mongodb connection string, this will happen just before settings UI is launched:

```
Traceback (most recent call last):
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\start.py", line 1151, in boot
    cli.main(obj={}, prog_name="openpype")
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\.venv\\lib\\site-packages\\click\\core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\.venv\\lib\\site-packages\\click\\core.py", line 782, in main
    rv = self.invoke(ctx)
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\.venv\\lib\\site-packages\\click\\core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\.venv\\lib\\site-packages\\click\\core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\.venv\\lib\\site-packages\\click\\core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\openpype\\cli.py", line 40, in settings
    PypeCommands().launch_settings_gui(dev)
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\openpype\\pype_commands.py", line 33, in launch_settings_gui
    settings.main(user_role)
  File "C:\\Users\\annat\\Documents\\Projects\\OpenPype\\sources\\OpenPype\\openpype\\tools\\settings\\__init__.py", line 27, in main
    app = QtWidgets.QApplication(sys.argv)
RuntimeError: Please destroy the QApplication singleton before creating a new QApplication instance.
```


[cuID:[OP-4545](https://app.clickup.com/t/37bv592)]
diff --git a/openpype/tools/settings/__init__.py b/openpype/tools/settings/__init__.py
index 3e77a8348a..67e509f116 100644
--- a/openpype/tools/settings/__init__.py
+++ b/openpype/tools/settings/__init__.py
@@ -24,7 +24,9 @@ def main(user_role=None):
             user_role, ", ".join(allowed_roles)
         ))
 
-    app = QtWidgets.QApplication(sys.argv)
+    app = QtWidgets.QApplication.instance()
+    if not app:
+        app = QtWidgets.QApplication(sys.argv)
     app.setWindowIcon(QtGui.QIcon(style.app_icon_path()))
 
     widget = MainWidget(user_role)
['openpype/tools/settings/__init__.py']