nixos/networking-interfaces-scripted: use read -r

...instead of plain read, which can cause issues.

See SC2162:
https://www.shellcheck.net/wiki/SC2162

nixos/modules/tasks/network-interfaces-scripted.nix

@@ -237,7 +237,7 @@ let
             preStop = ''
               state="/run/nixos/network/routes/${i.name}"
               if [ -e "$state" ]; then
-                while read cidr; do
+                while read -r cidr; do
                   echo -n "deleting route $cidr... "
                   ip route del "$cidr" dev "${i.name}" >/dev/null 2>&1 && echo "done" || echo "failed"
                 done < "$state"
@@ -246,7 +246,7 @@ let
 
               state="/run/nixos/network/addresses/${i.name}"
               if [ -e "$state" ]; then
-                while read cidr; do
+                while read -r cidr; do
                   echo -n "deleting address $cidr... "
                   ip addr del "$cidr" dev "${i.name}" >/dev/null 2>&1 && echo "done" || echo "failed"
                 done < "$state"