Disable Oliver's binary pacman repo by default

Currently building the package fails with an error 'qubes-r3.2: key "2043E7ACC1833B9C" is unknown'.
This also harmonizes the code with the current documentation: https://www.qubes-os.org/doc/templates/archlinux/#binary-packages-activation

(cherry picked from commit 5662d7e5fe7f5236a2623f725b7e0f908d26631f)

archlinux/PKGBUILD

@@ -91,7 +91,7 @@ package() {
   # Install pacman repository
   release=`echo $pkgver | cut -d '.' -f 1,2`
   echo "Installing repository for release ${release}"
-  install -m 644 $srcdir/PKGBUILD-qubes-repo-${release}.conf ${pkgdir}/etc/pacman.d/99-qubes-repository-${release}.conf
+  install -m 644 $srcdir/PKGBUILD-qubes-repo-${release}.conf ${pkgdir}/etc/pacman.d/99-qubes-repository-${release}.conf.disabled
 
   # Archlinux specific: enable autologin on tty1
   mkdir -p $pkgdir/etc/systemd/system/getty@tty1.service.d/
@@ -107,4 +107,3 @@ EOF
 }
 
 # vim:set ts=2 sw=2 et:
-