fix exports template

I need this patch to get /etc/exports written in correct format, see the example:

before:
```
# Managed by Puppet

# /srv/nfs01 10.0.1.1/24/srv/nfs01 10.0.1.1/24(rw,sync,no_root_squash)

# /srv/nfs01 10.0.2.1/24/srv/nfs01 10.0.2.1/24(rw,sync,no_root_squash)
```
after:
```
# Managed by Puppet

# /srv/nfs01 10.0.1.1/24
/srv/nfs01 10.0.1.1/24(rw,sync,no_root_squash)

# /srv/nfs01 10.0.2.1/24
/srv/nfs01 10.0.2.1/24(rw,sync,no_root_squash)
```