KEYCLOAK-2479 Avoid ZIPException during bigger load

common/src/main/java/org/keycloak/common/util/Base64Url.java

@@ -49,7 +49,8 @@ public class Base64Url {
                         "Illegal base64url string!");
         }
         try {
-            return Base64.decode(s);
+            // KEYCLOAK-2479 : Avoid to try gzip decoding as for some objects, it may display exception to STDERR. And we know that object wasn't encoded as GZIP
+            return Base64.decode(s, Base64.DONT_GUNZIP);
         } catch (Exception e) {
             throw new RuntimeException(e);
         }