[fractal] Update URL of gnome-nightly flatpak repo

[Alexandre Franke <afranke src gnome org>]

commit 0d0d7058f9f9768703a19c10a98f447180a4e949
Author: Aurabindo J <mail aurabindo in>
Date:   Sat Nov 23 09:25:57 2019 +0000

    Update URL of gnome-nightly flatpak repo

 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README.md b/README.md
index acfd3ecf..0e033629 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ First you need to make sure you have the GNOME SDK and Rust toolchain installed.
 ```
 # Add Flathub and the gnome-nightly repo
 flatpak remote-add --user --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
-flatpak remote-add --user --if-not-exists gnome-nightly https://sdk.gnome.org/gnome-nightly.flatpakrepo
+flatpak remote-add --user --if-not-exists gnome-nightly https://nightly.gnome.org/gnome-nightly.flatpakrepo
 
 # Install the gnome-nightly Sdk and Platform runtime
 flatpak install --user gnome-nightly org.gnome.Sdk org.gnome.Platform