[CST-6152] allow password change only if a challenge is resolved.

dspace-api/src/main/java/org/dspace/authenticate/X509Authentication.java

@@ -608,4 +608,9 @@ public class X509Authentication implements AuthenticationMethod {
         }
         return false;
     }
+
+    @Override
+    public boolean canChangePassword(Context context, String challenge) {
+        return false;
+    }
 }