[gimp] desktop: install 64x64 app icon.

[Jehan <jehanp src gnome org>]

commit b7c2fbe6a88342e2672c19c80566ce9d706f6980
Author: Jehan <jehan girinstud io>
Date:   Tue Jul 6 11:38:33 2021 +0200

    desktop: install 64x64 app icon.
    
    For some reason, this size was installed in the meson build, not the
    autotools one.

 desktop/Makefile.am | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/desktop/Makefile.am b/desktop/Makefile.am
index a8b13e704f..2fd6c64fca 100644
--- a/desktop/Makefile.am
+++ b/desktop/Makefile.am
@@ -34,6 +34,9 @@ icons32_DATA = 32x32/gimp.png
 icons48dir = $(DESKTOP_DATADIR)/icons/hicolor/48x48/apps
 icons48_DATA = 48x48/gimp.png
 
+icons64dir = $(DESKTOP_DATADIR)/icons/hicolor/64x64/apps
+icons64_DATA = 64x64/gimp.png
+
 icons256dir = $(DESKTOP_DATADIR)/icons/hicolor/256x256/apps
 icons256_DATA = 256x256/gimp.png