Made hadoop-hdfs-client dependency optional (#291)

Co-authored-by: Yannick Menager <4215831-ymenager@users.noreply.gitlab.com>
diff --git a/commons-vfs2/pom.xml b/commons-vfs2/pom.xml
index 1fb4b81..787bfaf 100644
--- a/commons-vfs2/pom.xml
+++ b/commons-vfs2/pom.xml
@@ -61,6 +61,7 @@
     <dependency>

       <groupId>org.apache.hadoop</groupId>

       <artifactId>hadoop-hdfs-client</artifactId>

+      <optional>true</optional>

     </dependency>

     <dependency>

       <groupId>org.apache.hadoop</groupId>