Just for future knowledge...if a tube of silicone says anything about preventing mold and mildew then it is the WRONG type. Many kitchen and bath silicones say that because those areas are prone to mildew/mold issues. Generally, window and door silicones do not say it, but there may be some out there that do have a mildewcide...always read the label.
And don't just read far enough to see that a tube is "100% silicone"...that sounds like it has to be free of anything but silicone, right? Wrong! A tube of silicone labeled 100% silicone can still have other stuff in it...like mildew preventers. Not sure how that can be legal, and it is really misleading, but I see it all the time.