Revert "BIGTOP-2839. Bump Hadoop version to 2.7.4"
Revert "BIGTOP-2839. Bump Hadoop version to 2.7.4"

This reverts commit 4b662c36a50f3e29b4be174a28e8f0c6051136a7.

welikecloud/bigtop,apache/bigtop,juju-solutions/bigtop,youngwookim/bigtop,sekikn/bigtop,youngwookim/bigtop,arenadata/bigtop,arenadata/bigtop,JunHe77/bigtop,panagiotisl/bigtop,apache/bigtop,panagiotisl/bigtop,welikecloud/bigtop,youngwookim/bigtop,JunHe77/bigtop,sekikn/bigtop,JunHe77/bigtop,apache/bigtop,mbalassi/bigtop,alaunay/bigtop,apache/bigtop,juju-solutions/bigtop,sekikn/bigtop,JunHe77/bigtop,welikecloud/bigtop,arenadata/bigtop,apache/bigtop,welikecloud/bigtop,alaunay/bigtop,youngwookim/bigtop,juju-solutions/bigtop,mbalassi/bigtop,panagiotisl/bigtop,panagiotisl/bigtop,juju-solutions/bigtop,alaunay/bigtop,arenadata/bigtop,mbalassi/bigtop,mbalassi/bigtop,alaunay/bigtop,sekikn/bigtop,sekikn/bigtop