Revert "Pin glusterfs-5 repo"

This reverts commit 476882dc9330b6d4ad42b22a998607a6d9678700.

Change-Id: I45df9137c76b2d2973d7ba104bc92014889887e8
diff --git a/defaults/linux_system_repo.yml b/defaults/linux_system_repo.yml
index d85aea1..74c5f41 100644
--- a/defaults/linux_system_repo.yml
+++ b/defaults/linux_system_repo.yml
@@ -68,7 +68,7 @@
     # Repo-component versions (if applicable)
     salt_version: 2017.7 # TODO should be deprecated variable after 2018.q4
     linux_system_repo_mcp_cassandra_version: '21x'
-    linux_system_repo_mcp_glusterfs_version_number: "5"
+    linux_system_repo_mcp_glusterfs_version_number: "3.8"
     linux_system_repo_mcp_saltstack_version_number: "${_param:salt_version}"
     linux_system_repo_mcp_ceph_codename: luminous
     linux_repo_contrail_component: oc40