[gnome-disk-utility] Build/install readme: Fix typo

[Kai Lüke <kailueke src gnome org>]

commit e92f1ba770fdaa976522d5e7415adf5c57012e21
Author: Kai Lüke <kailueke riseup net>
Date:   Tue Aug 11 22:21:11 2020 +0200

    Build/install readme: Fix typo

 INSTALL | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/INSTALL b/INSTALL
index 25dcf8cb..849dcc1d 100644
--- a/INSTALL
+++ b/INSTALL
@@ -61,7 +61,7 @@ You can also install the resulting Flatpak in your system:
   flatpak --user uninstall org.gnome.DiskUtility
 
 This runs/installs GNOME Disks built against UDisks and libblockdev from git
-but if you do not start a the new udisksd with the bwrap trick, 
+but if you do not start the new udisksd with the bwrap trick,
 the resulting Flatpak app will still use the UDisks version provided by the system. 
 That is because Flatpak cannot run the built UDisks as new system service.