rgw: RGWAccessKey::decode_json() preserves default value of 'active'

squid added the new "bool active" member that defaults to true, but
RGWAccessKey::decode_json() sets it to false when "active" isn't present

this is an issue for multisite when a squid zone replicates user
metadata from a master zone running reef

Fixes: https://tracker.ceph.com/issues/68985

Signed-off-by: Casey Bodley <cbodley@redhat.com>

src/rgw/rgw_common.cc

@@ -2994,7 +2994,9 @@ void RGWAccessKey::decode_json(JSONObj *obj) {
       subuser = user.substr(pos + 1);
     }
   }
-  JSONDecoder::decode_json("active", active, obj);
+  if (bool tmp = false; JSONDecoder::decode_json("active", tmp, obj)) {
+    active = tmp; // update only if "active" is present
+  }
   JSONDecoder::decode_json("create_date", create_date, obj);
 }