Fix UnparsedBlock properties when the header rewrites its prop.
Fix UnparsedBlock properties when the header rewrites its prop.

Kronuz/pyScss,Kronuz/pyScss,Kronuz/pyScss,hashamali/pyScss,cpfair/pyScss,hashamali/pyScss,Kronuz/pyScss,cpfair/pyScss,cpfair/pyScss,hashamali/pyScss