Update rebuilderd configuration for 0.9.1

roles/rebuilderd/templates/rebuilderd-sync.conf.j2

 [profile."archlinux-core"]
 distro = "archlinux"
 suite = "core"
-architecture = "x86_64"
+architectures = ["x86_64"]
 source = "https://europe.mirror.pkgbuild.com/$repo/os/$arch"
 
 [profile."archlinux-extra"]
 distro = "archlinux"
 suite = "extra"
-architecture = "x86_64"
+architectures = ["x86_64"]
 source = "https://europe.mirror.pkgbuild.com/$repo/os/$arch"
 excludes = [""]
 
 [profile."archlinux-testing"]
 distro = "archlinux"
 suite = "testing"
-architecture = "x86_64"
+architectures = ["x86_64"]
 source = "https://europe.mirror.pkgbuild.com/$repo/os/$arch"
 excludes = [""]
 
 [profile."archlinux-community"]
 distro = "archlinux"
 suite = "community"
-architecture = "x86_64"
+architectures = ["x86_64"]
 source = "https://europe.mirror.pkgbuild.com/$repo/os/$arch"
 excludes = ["cuda*", "tensorflow*", "*pytorch*", "*kube*", "python-tensorflow*"]
 
 [profile."archlinux-community-testing"]
 distro = "archlinux"
 suite = "community-testing"
-architecture = "x86_64"
+architectures = ["x86_64"]
 source = "https://europe.mirror.pkgbuild.com/$repo/os/$arch"
 excludes = ["cuda*", "tensorflow*", "*pytorch*", "*kube*", "python-tensorflow*"]