[gimp] configure.ac: post-release version bump to 2.9.9

[Michael Natterer <mitch src gnome org>]

commit e8dd20feda2d22f5612f568c9478546b37bb1561
Author: Michael Natterer <mitch gimp org>
Date:   Tue Dec 12 20:54:13 2017 +0100

    configure.ac: post-release version bump to 2.9.9

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 07d8309..bb572d8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -11,7 +11,7 @@ AC_PREREQ(2.54)
 
 m4_define([gimp_major_version], [2])
 m4_define([gimp_minor_version], [9])
-m4_define([gimp_micro_version], [8])
+m4_define([gimp_micro_version], [9])
 m4_define([gimp_real_version],
           [gimp_major_version.gimp_minor_version.gimp_micro_version])
 m4_define([gimp_version], [gimp_real_version])