[gegl] operations: add back color-enhance op that had fallen out

[Øyvind Kolås <ok src gnome org>]

commit b11a03051641cbec18144b9d53571b27655b0e01
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Sep 26 21:43:15 2017 +0200

    operations: add back color-enhance op that had fallen out

 operations/common/Makefile.am |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/operations/common/Makefile.am b/operations/common/Makefile.am
index e32fb6e..a83d30d 100644
--- a/operations/common/Makefile.am
+++ b/operations/common/Makefile.am
@@ -24,6 +24,7 @@ gegl_common_la_SOURCES =\
        c2g.c \
        checkerboard.c \
        dither.c \
+       color-enhance.c \
        color-rotate.c \
        color-temperature.c \
        color.c \