JERUSALEM — A rocket fired by Palestinian militants from the Gaza Strip killed a man inside Israel Thursday, Israeli medics said, in the first death from such an attack since Israel’s Gaza offensive last year. Such rocket fire once common but have become rare since the Israeli military’s campaign in the Gaza Strip last year, which aimed to bring an end to the attacks. Israel’s emergency service Magen David Adom said the man killed was about 30 years old and appeared to be a farm worker from Thailand employed in an agricultural community just north of Gaza. Thursday’s attack came on the same day as a visit to Gaza by Europe’s top diplomat, EU foreign policy chief Catherine Ashton, the first such visit by a senior official in more than a year. Ashton had just crossed into Gaza when the attack took place.