Update Entity.php

fix error:
   *Invalid parameter number: number of bound variables does not match number of tokens
when having :
    * @Grid\Column(field="client.id:countIf:2", type="boolean")
    * @Grid\Column(field="client.id:countIf:1", type="boolean")
Merge pull request #374 from dropdatabase/master

Multiple grid column having "countIf" throw doctrine exception