vlc plays only ONE frame of GIF, but not the sequence

[Vitaliy Kanev]

Steps to reproduce
------------------

Open the provided GIF (see test.txt for the link)

Expected behavior
-----------------

GIF sequence plays

Actual behavior
---------------

Only the first frame is played (a.k.a VLC considers this file as Legacy, single-frame GIF)

VLC version
-----------

vitalkanev@Doogle:~$ LANG=C vlc --version
VLC media player 3.0.2 Vetinari (revision 3.0.2-0-gd7b653cf14)
VLC version 3.0.2 Vetinari (3.0.2-0-gd7b653cf14)
Compiled by buildd on lgw01-amd64-005.buildd (May 15 2018 04:26:56)
Compiler: gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)
<warranty info snipped>
Written by the VideoLAN team; see the AUTHORS file.

"info.zip" contents
-------------------

Снимок экрана_2018-07-31_18-24-31.png <== gthumb 3.6.1 playing this GIF
Снимок экрана_2018-07-31-18-27-46.png <== vlc plating this GIF
debug.log <== output of `vlc -vvv <gif file>`
test.txt <== link to the gif (because it is way too big)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: vlc 3.0.2-0ubuntu0.1
ProcVersionSignature: Ubuntu 4.15.0-29.31-generic 4.15.18
Uname: Linux 4.15.0-29-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Thu Aug 2 13:54:50 2018
InstallationDate: Installed on 2018-07-15 (17 days ago)
InstallationMedia: Xubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: vlc
UpgradeStatus: No upgrade log present (probably fresh install)