Certificate file migration in multi-instance handling doesn't work from last release version 0.4.6

[zehnm]

Description

PR #35 doesn't work on the Remote Two device: the certificate file migration doesn't work.

• Instead of renaming the existing files, new certificates are generated.
• Then the connect() call runs into Error: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:2580)

INFO:config:Migrating configuration: connecting to device 'ShieldTV Wohnzimmer' (xxxxxxxxxxxx) to update manufacturer and device model
DEBUG:tv:[ShieldTV Wohnzimmer] Generated new certificate
DEBUG:tv:[ShieldTV Wohnzimmer] Retrieving device information from 192.168.16.191
DEBUG:tv:[ShieldTV Wohnzimmer] Android TV initialised
DEBUG:tv:[ShieldTV Wohnzimmer] Connecting Android TV xxxxxxxxxxxx on 192.168.16.191
DEBUG:androidtvremote2:Connected to ('192.168.16.191', 6466)
DEBUG:androidtvremote2:Connection lost. Error: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:2580)
DEBUG:androidtvremote2:Couldn't connect to 192.168.16.191:6466. Error: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:2580)
ERROR:tv:[ShieldTV Wohnzimmer] Invalid authentication for xxxxxxxxxxxx
WARNING:config:Could not migrate device configuration 'ShieldTV Wohnzimmer' (xxxxxxxxxxxx): device not found on network

Tasks:

• migrate certificate files before migrating the configuration file (which requires a connection to the device to retrieve manufacturer & model name)
• handle authentication error in migration to avoid misleading error message device not found on network

How to Reproduce

1. Install 0.4.6
2. Configure Android TV device
3. Stop integration
4. Update to current main branch
5. Restart integration
6. See failed migration

Expected behavior

Certificates and configration are successfully migrated from 0.4.6

Integration version

0.4.6

Additional context

No response