file command incorrectly identifies a gzipped file as being a Minix filesystem

In Ubuntu 14.04, the command `file` (1:5.14-2ubuntu3.3) incorrectly identifies a gzipped file as being a Minix filesystem.

Example:

```
$ file gzip-minix.eml
gzip-minix.eml: Minix filesystem, V3, 43470 zones
$ file -v
file-5.14
magic file from /etc/magic:/usr/share/misc/magic
```

The workaround I'm using is passing the `-k` (keep going) param to file.

```
$ file -k gzip-minix.eml
gzip-minix.eml: Minix filesystem, V3, 43470 zones\012- gzip compressed data, from Unix
```

In Ubuntu 16.04, however, the file is correctly identified.

```
$ file gzip-minix.eml
gzip-minix.eml: gzip compressed data, from Unix
$ file -v
file-5.25
magic file from /etc/magic:/usr/share/misc/magic
```

This bug has a description very similar to those reported in these URLs:

- https://bugzilla.redhat.com/show_bug.cgi?id=873997
- https://bugzilla.redhat.com/show_bug.cgi?id=758429

However, despite the very similar description, I didn't find any problem with the JPEG files attached in these bug reports.

Note: The error is occurring in about 1 gzipped file for each 60000 or 100000 files I have in my data filesystem. Because some of these files contain sensitive information, I'm attaching only one of them (an innocent example).