Brake bleed nipple leak?

Hi guys, in need for some help here.

I'm preparing my car for a trackday so i changed front pads with new DS2500s and bed them in, after that i found a little surprise at all four bleed nipples:

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This is the worst one, other 3 nipples are slightly less wet, but all of them are leaking at least a very small amount of brake fluid trough the center hole. I had brake fluid replaced half year ago but i havent noticed any leak until now that i changed the pads (maybe i wasn't paying enough attention), but brakes seem fine, have no spongy or soft feeling. I havent touched the bleed nipples at all during pad change, so its very wierd for nipples to be leaking just after pad change, don't you think?

Also tried to tighten the nipples a bit, but they seem pretty tight allready.

Anyone had any similar issues?

Any help would be really welcome!