Disable/Hide Cognos signin

[sdf]

HI,

Please let me know if it is possible to disable/hide the signin option as shown in the attachement.
We have multiple namespaces setup in config. True enough that if we set selectable false for the other authentication, this signin option will be gone. But we need the other authentication to be selectable for a particular reason but we don't want users to authenticate to it.

please advise.