By Joseph Campbell and Zohra Bensemra TROSTYANETS, Ukraine (Reuters) – The handmade sign on the gate warns “The cemetery is mined. Danger.” but residents of the formerly occupied town of Trostyanets in northern Ukraine still come to visit the fresh graves of family killed in the war. The graveyard in this town in Sumy region has only been partly made safe since Russian forces planted mines there as they pulled back in early April, cemetery manager Olena Matvienko said. “De-mining teams came later and de-mined it partially. Then they didn’t go further inside,” Matvienko said on Saturday, standi…