[gnome-builder] podman: enable by default on nightly

[Christian Hergert <chergert src gnome org>]

commit 2ee172a7dc809b10d9f49ba0aeca4792953fc00b
Author: Christian Hergert <chergert redhat com>
Date:   Tue May 7 08:51:11 2019 -0700

    podman: enable by default on nightly

 meson_options.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson_options.txt b/meson_options.txt
index 1e2c94943..36fcfc969 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -58,7 +58,7 @@ option('plugin_newcomers', type: 'boolean')
 option('plugin_notification', type: 'boolean')
 option('plugin_npm', type: 'boolean')
 option('plugin_phpize', type: 'boolean')
-option('plugin_podman', type: 'boolean', value: false)
+option('plugin_podman', type: 'boolean')
 option('plugin_python_pack', type: 'boolean')
 option('plugin_qemu', type: 'boolean')
 option('plugin_quick_highlight', type: 'boolean')