[gnome-photos] application: Add gegl:exposure to the list of required operations

[Debarshi Ray <debarshir src gnome org>]

commit 2a50c7cac941a317cb9433409e6436b1e3c437a5
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu Feb 9 23:40:33 2017 +0100

    application: Add gegl:exposure to the list of required operations
    
    We are going to use it in the following patches.

 src/photos-application.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/photos-application.c b/src/photos-application.c
index 8669f18..b52f72a 100644
--- a/src/photos-application.c
+++ b/src/photos-application.c
@@ -149,6 +149,7 @@ static const gchar *REQUIRED_GEGL_OPS[] =
   "gegl:buffer-sink",
   "gegl:buffer-source",
   "gegl:crop",
+  "gegl:exposure",
   "gegl:gray",
   "gegl:load",
   "gegl:nop",