package/Config.in: move flutter-gallery menu entry

flutter-gallery was erroneously placed under the "Graphic libraries"
section of the menu "Graphic libraries and applications (graphic/text)"
menu. However, as flutter-gallery is a flutter-based graphical user
interface (GUI) application, it is better suited to be placed under the
"Graphic applications" section.

Signed-off-by: Adam Duskett <adam.duskett@amarulasolutions.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 75d78e42259e46ca575f4a07879d3e68d2e3a811)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/Config.in

@@ -313,6 +313,7 @@ menu "Graphic libraries and applications (graphic/text)"
 comment "Graphic applications"
 	source "package/cage/Config.in"
 	source "package/cog/Config.in"
+	source "package/flutter-gallery/Config.in"
 	source "package/flutter-pi/Config.in"
 	source "package/fswebcam/Config.in"
 	source "package/ghostscript/Config.in"
@@ -346,7 +347,6 @@ comment "Graphic libraries"
 	source "package/fbset/Config.in"
 	source "package/fbterm/Config.in"
 	source "package/fbv/Config.in"
-	source "package/flutter-gallery/Config.in"
 	source "package/freerdp/Config.in"
 	source "package/graphicsmagick/Config.in"
 	source "package/imagemagick/Config.in"