[gnome-builder] plugins: Replace deprecated python3 Meson module with python module.

[Christian Hergert <chergert src gnome org>]

commit 4b8ab1072917c3b7262ae2831f9b53d630df5940
Author: David Strauss <david davidstrauss net>
Date:   Mon Jul 1 19:05:02 2019 -0700

    plugins: Replace deprecated python3 Meson module with python module.

 src/plugins/meson-templates/resources/meson.build        | 2 +-
 src/plugins/meson-templates/resources/src/meson-py.build | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/plugins/meson-templates/resources/meson.build 
b/src/plugins/meson-templates/resources/meson.build
index 172a2ea8e..ec9e69cbb 100644
--- a/src/plugins/meson-templates/resources/meson.build
+++ b/src/plugins/meson-templates/resources/meson.build
@@ -1,6 +1,6 @@
 project('{{name}}', {{if language == "c"}}'c',{{else if language == "c++"}}['cpp', 'c'],{{else if language 
== "vala"}}['c', 'vala'],{{else if language == "c♯"}}'cs',{{end}} 
           version: '{{project_version}}',
-    meson_version: '>= 0.49.0',
+    meson_version: '>= 0.50.0',
   default_options: [ 'warning_level=2',
 {{if language == "c"}}
                      'c_std=gnu11',
diff --git a/src/plugins/meson-templates/resources/src/meson-py.build 
b/src/plugins/meson-templates/resources/src/meson-py.build
index 8545d7674..3c0c356a5 100644
--- a/src/plugins/meson-templates/resources/src/meson-py.build
+++ b/src/plugins/meson-templates/resources/src/meson-py.build
@@ -9,10 +9,10 @@ gnome.compile_resources('{{name}}',
   install_dir: pkgdatadir,
 )
 
-python3 = import('python3')
+python = import('python')
 
 conf = configuration_data()
-conf.set('PYTHON', python3.find_python().path())
+conf.set('PYTHON', python.find_installation('python3').path())
 conf.set('VERSION', meson.project_version())
 conf.set('localedir', join_paths(get_option('prefix'), get_option('localedir')))
 conf.set('pkgdatadir', pkgdatadir)