BERLIN—German investigators on Wednesday raided the homes of two acquaintances of an ISIS terrorist group sympathizer who carried out a deadly shooting in Vienna in November, prosecutors said. The two men may have known about gunman Kujtim Fejzulai’s plans for the attack and failed to inform authorities, instead erasing material on their cellphones and social media platforms to cover up their connections to Fejzulai, federal prosecutors said in a statement. Four people were killed in the attack on Nov. 2 and the gunman also died. Twenty others, including a police officer, were wounded. Fejzulai, a dual national of Austria and North Macedonia, had a previous conviction for trying to join ISIS in Syria. Prosecutors identified the men whose homes were searched Wednesday in Osnabrueck and Kassel only as Kosovo citizen Blinor S. and German citizen Drilon G., in keeping with German privacy rules. Prosecutors didn’t say whether the pair had …