fix(networking): fixes for connect-ice script

- fix regular expression in connect-ice script
- replaces `writeText` with `writeShellScript`

system/networking.nix

@@ -122,12 +122,10 @@ in
 
   networking.networkmanager.dispatcherScripts = [
     {
-      #!/usr/bin/env bash
-      source = pkgs.writeText "connect_ice" ''
-        set -euxo pipefail
+      source = pkgs.writeShellScript "connect-ice" ''
         ACTION="$2"
         if [[ "$ACTION" == "up" ]]; then
-          if [[ "$CONNECTION_ID" =~ "WIFIonICE|WIFI@DB" ]]; then
+          if [[ "$CONNECTION_ID" =~ ^(WIFIonICE|WIFI\@DB)$ ]]; then
             ${pkgs.curl}/bin/curl 'https://login.wifionice.de/cna/logon' -sSL -X POST
           fi
         fi