NFC-46 Remove challenge from WebEidAuthToken

Author: SanderKondratjevNortal

src/main/java/eu/webeid/security/authtoken/WebEidAuthToken.java

@@ -33,7 +33,6 @@ public class WebEidAuthToken {
     private String signature;
     private String algorithm;
     private String format;
-    private String challenge;
 
     private String unverifiedSigningCertificate;
     private List<SupportedSignatureAlgorithm> supportedSignatureAlgorithms;
@@ -70,14 +69,6 @@ public void setFormat(String format) {
         this.format = format;
     }
 
-    public String getChallenge() {
-        return challenge;
-    }
-
-    public void setChallenge(String challenge) {
-        this.challenge = challenge;
-    }
-
     public String getUnverifiedSigningCertificate() {
         return unverifiedSigningCertificate;
     }