message not useful for sh:in list

[VladimirAlexiev]

(Moved from TopQuadrant/shacl#20 to this repo).

Go to http://shacl.org/playground/, select "example in Turtle" and add

schema:gender "hermaphrodite"

This constraint:

    sh:property [
        sh:path schema:gender ;
        sh:in ( "female" "male" ) ;
    ] ;

Causes this result:

[
	a sh:ValidationResult ;
	sh:resultSeverity sh:Violation ;
	sh:sourceConstraintComponent sh:InConstraintComponent ;
	sh:sourceShape _:n3 ;
	sh:focusNode <http://example.org/ns#Bob> ;
	sh:value "hermaphrodite" ;
	sh:resultPath schema:gender ;
	sh:resultMessage "Value is not in Blank node _:n11" ;
] .

"Blank node _:n11" in sh:resultMessage is not very useful.