Earlier this month I spent a week in Sicily, driving south from Palermo to Agrigento and then east to Syracuse and Messina. It was my first visit to Sicily in 17 years and, given the media reports, I had expected to find the island crowded with migrants from Africa. In fact, I saw none, other than those I glimpsed in a fenced-off processing centre at the quayside in Agrigento, the first port of call for many migrants who arrive in Sicily.