Hi Tim,
You can do that in 2 ways as firstly unwrapping the widget and removing the line of code which is not needed by as alert message and again wrapping it with the help of any IDE which is used by you.
or
you can do it through CSS as for that particular javascript or HTML snippet add a class and then check the alert message div and make is display none.if it is the second div of the snippet then you can do it in a format below add error to the snippet.
.error>div{
display:none;
}
hope this helps