runfix(backup): prevent exporting undefined self user id [WPB-17558]

[V-Gira]

WPB-17558 [Web] Backup - Messages from self user have an undefined sender ID

Description

Checklist

• [ ] mentions the JIRA issue in the PR name (Ex. [WPB-XXXX])
• [ ] PR has been self reviewed by the author;
• [ ] Hard-to-understand areas of the code have been commented;
• [ ] If it is a core feature, unit tests have been added;

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud