[poppler] Poppler 0.26.1 released

[Albert Astals Cid]

Available from
http://poppler.freedesktop.org/poppler-0.26.1.tar.xz

Changes against 0.26.0:
core:
 * Use field value V for radio buttons. Bug #75979
 * Fix extraction of text in some files. Bug #78145
 * Only add annotations of the current page when splitting. Bug #77549

build system:
 * autoconf: Fix libopenjpeg 1.5 detection on some systems. Bug #78389

glib:
 * Fix multiple definition of PopplerTextSpan

Cheers,
  Albert