ACCUMULO-1257 stopped updating time for bulk import when there are no files

git-svn-id: https://svn.apache.org/repos/asf/accumulo/branches/1.5@1468098 13f79535-47bb-0310-9956-ffa450edef68
ACCUMULO-1257 stopped updating time for bulk import when there are no files

git-svn-id: https://svn.apache.org/repos/asf/accumulo/trunk@1468100 13f79535-47bb-0310-9956-ffa450edef68