[gthumb] meson: avoid unnecessary glib deprecation warnings

[Paolo Bacchilega <paobac src gnome org>]

commit 1e5383c3429a0d8fb1d727ca7ac866cc266fec09
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Mon Apr 5 11:31:06 2021 +0200

    meson: avoid unnecessary glib deprecation warnings

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index d6b3f505..78e2749d 100644
--- a/meson.build
+++ b/meson.build
@@ -315,7 +315,7 @@ config_inc = include_directories('.')
 
 # C/C++ args
 
-c_args = []
+c_args = [ '-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_54' ]
 cpp_args = []
 if get_option('buildtype').contains('debug')
   warn_deprecated = get_option('warn-deprecated')