Fix check for empty string

cmd/mytoken-server/mytoken-setup/setup.go

internal/config/config.go

internal/db/db.go

internal/db/dbrepo/authcodeinforepo/state/state.go

...brepo/supertokenrepo/transfercoderepo/pollingCodeTmpST.go

...l/db/dbrepo/supertokenrepo/transfercoderepo/proxytoken.go

internal/endpoints/revocation/revocationEndpoint.go

internal/endpoints/token/access/accessTokenEndpoint.go

internal/endpoints/token/super/transferEndpoint.go

internal/oidc/revoke/revoke.go

internal/utils/ctxUtils/token.go

shared/supertoken/pkg/stid/stid.go

shared/supertoken/pkg/supertoken.go

shared/supertoken/restrictions/restriction.go