fix(nilportugues#74): deprecation warning removed

Author: roelfsche

src/Syntax/Column.php

@@ -112,7 +112,7 @@ public function getAlias()
  */
  public function setAlias($alias)
  {
- if (0 == \strlen($alias)) {
+ if (empty($alias) || 0 == \strlen($alias)) {
  $this->alias = null;
 
  return $this;