Remove unused import

h2/src/main/org/h2/expression/ConditionInConstantSet.java

@@ -9,7 +9,6 @@ package org.h2.expression;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.TreeSet;
-import org.h2.engine.Database;
 import org.h2.engine.Session;
 import org.h2.index.IndexCondition;
 import org.h2.message.DbException;