[niepce] README: update requirements

[Hubert Figuière <hub src gnome org>]

commit b61c1f64c851dd02904d0f77ffdb22ec400d6b54
Author: Hubert Figuière <hub figuiere net>
Date:   Thu Sep 26 23:09:32 2019 -0400

    README: update requirements

 README | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/README b/README
index 420378c..a5b3061 100644
--- a/README
+++ b/README
@@ -37,7 +37,7 @@ libxml2 > 2.5.0
 boost 1.60
 exempi >= 2.4.0
 libopenraw >= 0.1.0
-gegl >= 0.3.0
+gegl >= 0.4.0
 babl
 libgphoto2
 gexiv2 >= 0.10 (as required by rexiv2)
@@ -45,7 +45,7 @@ gexiv2 >= 0.10 (as required by rexiv2)
 Niepce is being developed on Linux. It should build and work on other
 UNIX systems.
 
-If you want to build using flatpak-build, use flatpak/org.gnome.Niepce.json.
+If you want to build using flatpak-builder, use flatpak/org.gnome.Niepce.json.
 
 Getting the code
 ----------------