OSBA fix for issue #1329 (crash at 128 kbps)

• Related issues: #1329 (closed)
• Requested reviewers: @weckbecker , @fotopoulou

Reason why this change is needed

• This may be a direct copy from the issue.

Description of the change

• Protection check to avoid assert

Affected operating points

• OSBA 128 kbps
• BE for cases where crash does not happen