FIX separator line is shown when you don't use a nib (ios7)

Hi @nxthbgthng!
I found that use of the category without a nib(emptyViewShouldBeShown == emptyViewIsShown) is TRUE and returns without hide the separator

Sample code (a simple _uitableviewcontroller_):

```
 - (void)viewDidLoad
 {
    [super viewDidLoad];
    [self.tableView registerClass:[FriendsTableCell class] forCellReuseIdentifier:kCELL_STRING];
    self.tableView.rowHeight = kCELL_HEIGHT;
    
    // My Custom VIew / View Controller embed in the table view
    DescriptionVC *descriptionVC = [[DescriptionVC alloc] init];
    [descriptionVC view];
    descriptionVC.imageView.image = [UIImage imageNamed:@"friendsDesc"];
    descriptionVC.label.text = LS(@"FriendsDescription");
    [descriptionVC setLoadingMode:YES];

    self.tableView.nxEV_emptyView = descriptionVC.view; 
    self.tableView.nxEV_hideSeparatorLinesWheyShowingEmptyView = YES;
 }
```