[gnome-sdk-images] Revert "Don't autoreconf vala either, since it also shouldn't be needed anymore."

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ede2eb9c28f72d73361d11e088ea1da5a59d77a6
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Thu Jun 14 13:13:10 2018 -0500

    Revert "Don't autoreconf vala either, since it also shouldn't be needed anymore."
    
    This reverts commit 6671e05b2be8b5ed13d890e250961c04c266e539.

 org.gnome.Sdk.json.in | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 66ed30d..383e6cb 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -195,6 +195,11 @@
                 {
                     "type": "patch",
                     "path": "vala-no-valadoc.patch"
+                },
+                {
+                    "type": "script",
+                    "commands": [ "autoreconf -v" ],
+                    "dest-filename": "autogen.sh"
                 }
             ]
         },