Detailed case export file is empty when cases with unknown previous hospitalization entries

[kwa20]

Bug Description

When previous hospitalizations are entered where location data is unknown, detailed case exports produce an empty file.

Steps to Reproduce

1. Create a case
2. Enter a previous hospitalization
3. Set region, district and hospital to unknown
4. Perform a detailed export where the created case is included
5. Check the exported file

Expected Behavior

Values should be exported as unknown

Screenshots

System Details

• Device:
• SORMAS version: 1.63.0
• Android version/Browser: firefox
• Server URL: test1401.sormas-oegd.de
• User Role: admin, national user

Additional Information

[roxanamlendea]

Validated ticket on the latest version of Sormas 1.64.0-SNAPSHOT on environment test.sormas.netzlink.com and test-de.sormas.netzlink.com.