Nope, gel eyeliner is slick enough and doesn’t need any more liquid before applying it to your eye. The only reason why you might add water to your eyeliner is if it was dried up and old. However, if this is the case we might suggest buying a new eyeliner.
Adding water to gel eyeliner can make it less opaque and harder to apply. Use the eyeliner how it was intended - with a dry brush!