configfile: drop superflous Printf

Before:

  $ gocryptfs -fsck .
  LoadConfFile: ReadFile: &os.PathError{Op:"open", Path:"/var/tmp/check-gocryptfs/scratchdev/gocryptfs.conf", Err:0xd}
  Cannot open config file: open /var/tmp/check-gocryptfs/scratchdev/gocryptfs.conf: permission denied

After:

  $ gocryptfs -fsck .
  Cannot open config file: open /var/tmp/check-gocryptfs/scratchdev/gocryptfs.conf: permission denied

internal/configfile/config_file.go

@@ -131,7 +131,6 @@ func Load(filename string, password []byte) ([]byte, *ConfFile, error) {
 	// Read from disk
 	js, err := ioutil.ReadFile(filename)
 	if err != nil {
-		fmt.Printf("LoadConfFile: ReadFile: %#v\n", err)
 		return nil, nil, err
 	}