mockftpserver: Remove pom.xml files am: 1fcee32776 am: 6944975bdd am: 59fc86a72d

Original change: https://android-review.googlesource.com/c/platform/external/mockftpserver/+/1817967

Change-Id: I83e8e60a18300c413219419a8c905c0f1c1f3043