fixing issue with optional mode in request parser

Author: dr4hcu5-jan

internal/jwt/validator.go

@@ -186,6 +186,9 @@ func (v *Validator) ParseHTTPRequest(r *http.Request) (accessToken jwt.Token, re
 	case errors.Is(err, jwt.ErrInvalidIssuer()):
 		return nil, &ErrJWTInvalidIssuer
 	case jws.IsVerificationError(err):
+		if v.IsOptional() {
+			return nil, nil
+		}
 		panic("unable to verify jwt")
 	case errors.Is(err, jwt.ErrInvalidJWT()):
 		res := ErrJWTMalformed