Remove unused use

Signed-off-by: Michal Čihař <michal@cihar.com>

Author: nijel

src/Components/CaseExpression.php

@@ -8,7 +8,6 @@
  */
 namespace SqlParser\Components;
 
-use SqlParser\Context;
 use SqlParser\Component;
 use SqlParser\Parser;
 use SqlParser\Token;