[pygobject] build: bump glib requirement to 2.48

[Christoph Reiter <creiter src gnome org>]

commit 464889c874ccb0129d9ff9240094974f8030fa4b
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Tue Nov 20 19:07:38 2018 +0100

    build: bump glib requirement to 2.48
    
    It's the one shipped with Ubuntu 16.04, which is the oldest distro
    we run tests on.

 meson.build | 2 +-
 setup.py    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index b942d904..5271ce96 100644
--- a/meson.build
+++ b/meson.build
@@ -17,7 +17,7 @@ python = pymod.find_installation(get_option('python'))
 
 python_dep = python.dependency()
 
-glib_version_req = '>= 2.38.0'
+glib_version_req = '>= 2.48.0'
 gi_version_req = '>= 1.46.0'
 pycairo_version_req = '>= 1.11.1'
 libffi_version_req = '>= 3.0'
diff --git a/setup.py b/setup.py
index a3e49481..6a558175 100755
--- a/setup.py
+++ b/setup.py
@@ -42,7 +42,7 @@ from distutils.spawn import find_executable
 
 
 PYGOBJECT_VERISON = "3.31.2"
-GLIB_VERSION_REQUIRED = "2.38.0"
+GLIB_VERSION_REQUIRED = "2.48.0"
 GI_VERSION_REQUIRED = "1.46.0"
 PYCAIRO_VERSION_REQUIRED = "1.11.1"
 LIBFFI_VERSION_REQUIRED = "3.0"