ceph: remove redundant csi statefulset template path vars
ceph: remove redundant csi statefulset template path vars

This commit removes redundant `RBDProvisionerSTSTemplatePath` and
`CephFSProvisionerSTSTemplatePath` variables which were forgetten to
be removed in https://github.com/rook/rook/pull/5982 when csi support
for k8s 1.13 was removed.

Signed-off-by: Rakshith R <2c7b05ed1488c7110901626c2c56645675e22767@redhat.com>

rook/rook,rook/rook,rook/rook,rook/rook,rook/nfs,rook/nfs,rook/rook,rook/nfs