It probably just noticed that this site doesn't use https (hyper text transfer protocol secure) and decided to warn you about it. I think most major browsers have that kind of behavior as standard now.
Shouldn't really be a big issue on an obscure website like this (although someone could in theory snatch your password as it's being sent unencrypted), but if you ever come across online stores or any other site that asks for a lot of information and their address looks like http://www.example.com instead of https://www.example.com, then run away.
"I only read American. I want my fantasy pure." - Dave