nix: update to 1.6.1.

srcpkgs/nix/template

@@ -1,7 +1,7 @@
 # Template file for 'nix'
 pkgname=nix
-version=1.6
-revision=2
+version=1.6.1
+revision=1
 build_style=gnu-configure
 # Use /nix/var as suggested by the official Manual.
 configure_args="--localstatedir=/nix/var"
@@ -37,7 +37,7 @@ maintainer="Juan RP <xtraeme@gmail.com>"
 license="MIT"
 homepage="http://nixos.org/nix/"
 distfiles="http://nixos.org/releases/nix/nix-${version}/nix-${version}.tar.xz"
-checksum=2e451a6ad0b43997d8df71d29a7d20ef42f7715fe16efbf4b53bdcdd1d5227fe
+checksum=31d15f99b2405924a4be278334cc973a71999303631e6798c1d294db9be4bf84
 
 post_install() {
 	# Remove unused stuff.