Fix failing test in SQLite.

SQLite does not handle subqueries in virtual fields well. However, the
original issue was that the generated query was invalid which
find(first) will still catch.

lib/Cake/Test/Case/Model/ModelReadTest.php

@@ -7864,7 +7864,7 @@ public function testVirtualFieldSubqueryReservedWords() {
 			'sub_test' => $sub
 		);
 
-		$result = $user->field('sub_test', array('id' => 1));
+		$result = $user->find('first');
 		$this->assertNotEmpty($result);
 	}