FV: authorized-by referencing a constant failure

[rsoeldner]

reported by @EnoF:

               (defconst testname: string 'ks)

               (defun test:bool ()
                 @model[(property (authorized-by testname))]
                 (enforce-guard (create-module-guard "governance")))

results in:

could not parse (authorized-by testname): in (authorized-by testname), couldn't find property named authorized-by