Merge pull request #51 from bedroge/stat_mounted

Add note about `cvmfs_config stat`

Author: boegel

docs/03_stratum1_proxies.md

@@ -393,7 +393,8 @@ See the [CernVM-FS documentation](https://cvmfs.readthedocs.io/en/stable/cpt-con
 Now you can test your new configuration by checking if you can still access the repository. 
 Do `sudo cvmfs_config chksetup` to again test the configuration, 
 including access to all configured Stratum 1 servers through all configured proxy servers.
-Furthermore, to confirm you are really using your Squid proxy (and to see which if there are more than one), you can do:
+Furthermore, to confirm you are really using your Squid proxy (and to see which if there are more than one),
+make sure your repository is mounted (e.g. by doing an `ls`) and then run:
 ```
 cvmfs_config stat -v repo.organization.tld
 ```