By Sabine Siebold PRISTINA/MITROVICA (Reuters) – NATO is ready to ramp up troops in Kosovo if tensions among minority Serbs flare again, the deputy commander of the alliance’s peacekeeping mission (KFOR) said on Tuesday as a deadline in a spat with the government over car license plates approaches. “We are vigilant and ready to act…if we have an increase of tensions, but we can also draw on reserve forces…that we can call in at short notice,” Brigadier General Luca Piperni told reporters at KFOR headquarters in the capital Pristina. Unrest among Kosovo Serbs over a requirement for them to …