[gnome-photos] build: Bump minimum Meson version to 0.50.0

[Debarshi Ray <debarshir src gnome org>]

commit b3b0da71e3cc76205ddf592170595b0fe3a18e66
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu May 30 13:28:03 2019 +0000

    build: Bump minimum Meson version to 0.50.0
    
    Silences the following WARNING:
      Project targetting '>= 0.47.0' but tried to use feature introduced
        in '0.50.0': install arg in configure_file
    
    Fallout from cc5584327aacd6590ff69eeb5a130c41843ce3c8

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index c91ffa57..92086df9 100644
--- a/meson.build
+++ b/meson.build
@@ -3,7 +3,7 @@ project(
   version: '3.33.1',
   license: 'GPL3+',
   default_options: 'buildtype=debugoptimized',
-  meson_version: '>= 0.47.0',
+  meson_version: '>= 0.50.0',
 )
 
 photos_prefix = get_option('prefix')