nixos/activation: allowed quoted values in /etc/os-release

Author: peterhoeg

nixos/modules/system/activation/switch-to-configuration.pl

@@ -59,7 +59,7 @@
 # This is a NixOS installation if it has /etc/NIXOS or a proper
 # /etc/os-release.
 die "This is not a NixOS installation!\n" unless
-    -f "/etc/NIXOS" || (read_file("/etc/os-release", err_mode => 'quiet') // "") =~ /ID=nixos/s;
+    -f "/etc/NIXOS" || (read_file("/etc/os-release", err_mode => 'quiet') // "") =~ /ID="?nixos"?/s;
 
 openlog("nixos", "", LOG_USER);