title: White space before separator line into my TableView
body: <p>I have a question about UITableView...
  I have a UITableViewController and I created a custom cell.
  When I visualize the tableView I see a little white space before the separator line as you can see into this screenshot:</p>
  
  <p><img src="https://i.stack.imgur.com/QfoN1.png" alt="enter image description here"></p>
  
  <p>Why? It is a default visualize? 
  Can I change something to remove this white left padding?</p>