Fix registry_storage_provider.redirect check

[gogolok]

Instead of checking for the string "true", check whether the statement
is true.

[vmwclabot]

@gogolok, you must sign our contributor license agreement before your changes are merged. Click here to sign the agreement. If you are a VMware employee, read this for further instruction.

[vmwclabot]

@gogolok, VMware has approved your signed contributor license agreement.