Fix shell for keystone user for rsync to work

Fix shell for keystone user to /bin/bash for rsync to work
between control nodes for fernet and credential keys sync

Change-Id: I5a1bd9cdcb7c11400c683a9b252ce9c3eb6cdafa
Related-PROD: PROD-22887
diff --git a/linux/system/users/keystone.yml b/linux/system/users/keystone.yml
index 14e38dd..cda4c36 100644
--- a/linux/system/users/keystone.yml
+++ b/linux/system/users/keystone.yml
@@ -8,7 +8,7 @@
           home: /var/lib/keystone
           uid: 301
           gid: 301
-          shell: /bin/false
+          shell: /bin/bash
           system: True
       group:
         keystone: