Merge pull request #63 from danubetech/fix/header-validation

Header validation issue fixed

Author: azuzi

src/main/java/com/danubetech/verifiablecredentials/jwt/JwtObject.java

@@ -50,7 +50,7 @@ public JwtObject(JWTClaimsSet payload, JWSObject jwsObject, String compactSerial
 
 	private String sign(JWSSigner jwsSigner, JWSAlgorithm alg, String kid, boolean canonicalize) throws JOSEException {
 
-		if(this.header == null || this.header.getKeyID() == null || this.header.getAlgorithm() == null){
+		if(this.header == null  || this.header.getAlgorithm() == null){
 			JWSHeader.Builder jwsHeaderBuilder = new JWSHeader.Builder(alg);
 			jwsHeaderBuilder.type(JOSEObjectType.JWT);
 			if (kid != null) jwsHeaderBuilder.keyID(kid);