Fix logic for 'at least one' item

We only show global header/footer if there's at least one item to display.  The header was fine already, but we weren't considering other cases where there were items found in order to decide to display the footer.

So if you had no header visible, but wanted a footer, it wouldn't show up.

VirtualListView/PositionalViewSelector.cs

@@ -33,7 +33,7 @@ int GetTotalCount()
 
 		var sum = 0;
 
-		var hasAtLeastOneItem = false;
+		//var hasAtLeastOneItem = false;
 		var numberOfSections = Adapter.GetNumberOfSections();
 
 		if (HasGlobalHeader && numberOfSections > 0)
@@ -50,7 +50,6 @@ int GetTotalCount()
 					// If we found one, we can stop looping
 					// since we just care to calculate a spot
 					// for the header cell if the adapter isn't empty
-					hasAtLeastOneItem = true;
 					break;
 				}
 			}
@@ -72,7 +71,7 @@ int GetTotalCount()
 
 		// Only count footer if there is already at least one item
 		// otherwise the adapter is empty and we shouldn't count it
-		if (HasGlobalFooter && hasAtLeastOneItem)
+		if (HasGlobalFooter && sum > 0)
 			sum += 1;
 
 		return sum;