[evince] build: Bump requirement of meson version

[Germán Poo-Caamaño <gpoo src gnome org>]

commit 189eef4781ed3814d884b22fbfdbddedce877e82
Author: Germán Poo-Caamaño <gpoo gnome org>
Date:   Sun Sep 29 11:16:42 2019 -0300

    build: Bump requirement of meson version
    
    We were already using a feature from 0.50

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 1bed171f..65835e2d 100644
--- a/meson.build
+++ b/meson.build
@@ -3,7 +3,7 @@ project(
   version: '3.33.0',
   license: 'GPL2',
   default_options: 'buildtype=debugoptimized',
-  meson_version: '>= 0.49.0',
+  meson_version: '>= 0.50.0',
 )
 
 ev_name = meson.project_name().to_lower()