Print stack trace instead of adding to log message

Author: oliemansm

graphql-java-kickstart/src/main/java/graphql/kickstart/execution/subscriptions/apollo/SubscriptionConnectionInitCommand.java

@@ -19,7 +19,7 @@ public void apply(SubscriptionSession session, OperationMessage message) {
       connectionListeners.forEach(it -> it.onConnect(session, message));
       session.sendMessage(new OperationMessage(Type.GQL_CONNECTION_ACK, message.getId(), null));
     } catch (Throwable t) {
-      log.error("Cannot initialize subscription command '{}': {}", message, t);
+      log.error("Cannot initialize subscription command '{}'", message, t);
       session.sendMessage(new OperationMessage(Type.GQL_CONNECTION_ERROR, message.getId(), t.getMessage()));
     }
   }