package/libepoxy: bump to version 1.5.7

package/libepoxy: bump to version 1.5.7

This update includes a build fix for the RaspberryPi 4 (from 1.5.7)
and a fix for the GL library loader when GLX is involved (from 1.5.6)
Release notes:

  https://github.com/anholt/libepoxy/releases/tag/1.5.6
  https://github.com/anholt/libepoxy/releases/tag/1.5.7

Signed-off-by: Adrian Perez de Castro <aperez@igalia.com>
[francois.perrad@gadz.org: fix indent in hash file]
Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
[yann.morin.1998@free.fr: meld Adrian and François' patches together]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>