Remove unused import in DocIndexer

Change-Id: I767af51950957e16e7c7d9aac573c2a03cba1641
diff --git a/lib/asciidoctor/java/DocIndexer.java b/lib/asciidoctor/java/DocIndexer.java
index 1bf3ac7..7f9f77a 100644
--- a/lib/asciidoctor/java/DocIndexer.java
+++ b/lib/asciidoctor/java/DocIndexer.java
@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import java.io.BufferedInputStream;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;