Editing database connection params doesn't update actual connection string

[PauliusJaskutelis]

Describe the bug
Connection created in "Add New Connection" form.
When editing connection and changing "Other parameters" field, testing and saving the settings, actual connection string is not updated with the new changed parameters.
For example if I add -RO flag to the parameters and save it i will still be able to create, update and delete records using that connection.

To Reproduce
Steps to reproduce the behavior:

1. Go to "Edit Connection" form.
2. Change "Other parameters" field with adding or removing -RO flag.
3. Test connection and save the settings.
4. See newly added/removed parameter doesn't affect the connection. It should use the connection string it was started on when initializing.

Expected behavior
The parameters are updated in the connection string it uses to connect to the database server, on setting save button.

Screenshots

1. Editing database parameters with -RO flag, testing connection and saving settings.
   

2. Still able to create, update and delete records.