Remove unused import

Author: markharwood

server/src/main/java/org/elasticsearch/index/mapper/StringFieldType.java

@@ -37,7 +37,6 @@
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.query.support.QueryParsers;
 
-import java.io.IOException;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;