By Hyunjoo Jin SAN FRANCISCO (Reuters) – SpaceX chief Elon Musk warned there was a high chance the company’s Starlink satellite broadband service could be “targeted” in Ukraine, which has been hit by Russian invasion. The warning came days after an internet security researcher warned that devices used for satellite communications could become “beacons” that Russia could target for airstrikes. “Important warning: Starlink is the only non-Russian communications system still working in some parts of Ukraine, so probability of being targeted is high. Please use with caution,” Musk tweeted. He aske…