Update Update.java

Add necessary Select import for Update with Select

Author: CeeKayGit

src/main/java/net/sf/jsqlparser/statement/update/Update.java

@@ -31,6 +31,7 @@
 import net.sf.jsqlparser.statement.select.FromItem;
 import net.sf.jsqlparser.statement.select.Join;
 import net.sf.jsqlparser.statement.select.PlainSelect;
+import net.sf.jsqlparser.statement.select.Select;
 
 /**
  * The update statement.