Thanks for your question. First and foremost I should tell you that you do not need to worry at all because removal of one testicle is surely not going to make you an infertile man. You will surely have babies if it is your desire. There are various such cases that I know where people do not have one testicle but still they are proud fathers of their children.
However, one thing you should remember that with the removal of one of your testicle, the sperm count of yours will decrease as compared to someone having two testicles. You must have read about this in your knoppix manufacturing office itself while sitting at your computer. This decrease in sperm count will decrease your masturbation levels. In case you want to masturbate on a frequent basis then it might prevent you because your testicle will not be able to produce the right amount of sperm needed for a pleasurable masturbation. It might also displease your partner in case she finds that you have only one testicle. Most of the women love excess of sperm on their body or mouth after having the sexual intercourse. In such a case, you might displease a woman. However, one thing is for sure that if you are majorly concerned as to whether or not you will be a proud father of your children then I must assure you that you will certainly be a father someday in your life. Your sperm count will not prevent you from becoming one because for impregnating a woman, lot of sperm count is not required. Just a few will serve the purpose fully. Have a good day!