[gnome-disk-utility] Build/install readme: Install Flatpak as user

[Kai Lüke <kailueke src gnome org>]

commit 649cab4c9c25ed110b7a33a3d59674a6c0d19b82
Author: Kai Lüke <kailueke riseup net>
Date:   Tue Jul 23 00:18:40 2019 +0200

    Build/install readme: Install Flatpak as user

 INSTALL | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/INSTALL b/INSTALL
index cd5420d8..888bf871 100644
--- a/INSTALL
+++ b/INSTALL
@@ -50,7 +50,7 @@ Using Flatpak to build and run GNOME Disks and UDisks (both from web sources):
   flatpak-builder --run app flatpak/org.gnome.DiskUtility.json gnome-disks
   # or LD_LIBRARY_PATH=app/files/lib/ app/files/bin/gnome-disks to run without any sandboxing
 You can also install the resulting Flatpak in your system:
-  flatpak-builder --force-clean --install app flatpak/org.gnome.DiskUtility.json
+  flatpak-builder --force-clean --user --install app flatpak/org.gnome.DiskUtility.json
   flatpak run org.gnome.DiskUtility
   # and uninstall it when it's not needed anymore:
   flatpak --user uninstall org.gnome.DiskUtility