[pygobject] build: Set PLATFORM_VERSION again to 3.0

[Colin Walters <walters src gnome org>]

commit 35b5a85aad91f48935dd49fee60d69e6184eff2c
Author: Colin Walters <walters verbum org>
Date:   Tue Jan 14 16:33:38 2014 -0500

    build: Set PLATFORM_VERSION again to 3.0
    
    We are installing headers to:
    /usr/include/pygobject-$(PLATFORM_VERSION)/pygobject.h
    
    If the variable isn't set, then things attempting to use pygobject
    obviously fail.
    
    This was a regression from a build system refactoring.

 gi/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gi/Makefile.am b/gi/Makefile.am
index d4c7c30..f1a79bd 100644
--- a/gi/Makefile.am
+++ b/gi/Makefile.am
@@ -1,3 +1,5 @@
+PLATFORM_VERSION = 3.0
+
 SUBDIRS = \
        repository \
        overrides \