[babl] export-symbold: add babl_space_get_gamma

[Øyvind "pippin" Kolås <ok src gnome org>]

commit fe2446a0b36e1daf5de0099d6644b4a5ade03498
Author: Øyvind Kolås <pippin gimp org>
Date:   Thu Jul 9 17:36:07 2020 +0200

    export-symbold: add babl_space_get_gamma

 export-symbols | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/export-symbols b/export-symbols
index 9123e7e36..82269f5aa 100644
--- a/export-symbols
+++ b/export-symbols
@@ -56,6 +56,7 @@ babl_space_to_icc
 babl_space_with_trc
 babl_space_is_cmyk
 babl_space_is_gray
+babl_space_get_gamma
 babl_icc_make_space
 babl_icc_get_key
 babl_ticks