Build with updated girara.
* gnu/packages/pdf.scm (zathura): Update to 0.5.4.
* gnu/packages/patches/zathura-use-struct-initializers.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it here.
* gnu/packages/pdf.scm (zathura): Use it here.
Change-Id: I5975d993b92a1a77ed35df2206acb93219138cff
Signed-off-by: Christopher Baines <mail@cbaines.net>