Provide default base url if is none in the legacy prefs

[luhmirin-s]

JIRA ticket
Will be released in: 2025.3.0

Root cause analysis (for bugfixes only)

First known affected version: 2025.3.0

• On a fresh install, there is no URL in the legacy prefs and no default value was provided.

Notable changes

• Add default value when attempting to read value from the legacy URL prefs.

Testing guidance

• Have a fresh install. Try to log in.

Additional work checklist

• Effect on other features and security has been considered
• Design document marked as "In development" (if applicable)
• External (Gitbook) and internal (Confluence) Documentation is up to date (or ticket created)
• Test cases in Testiny are up to date (or ticket created)
• Other teams notified about the changes (if applicable)

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud