Fix the real cause of the persistent "1 extension edited" false positive

The previous fix (trimming the Name comparison) was real but not the
actual culprit here. loadExtensions()'s fallback for a device with no
pstn-permissions.conf entry — the normal, default state for any
extension never granted PSTN access — set restrict: "none", which
isn't one of the dropdown's five valid values (full/restricted/
restricted-in/restricted-out/internal). The <select> silently fell
back to its first option ("full") while the underlying model kept
"none", so the mismatch reappeared identically on every load
regardless of caching, matching a persistent bug survives hard
refresh and a private window. Use "internal" instead, matching the
documented default and the value the dropdown actually supports.

services/security-dashboard.sh

@@ -3066,7 +3066,7 @@ async function loadExtensions() {
     eaDevices.forEach(d => {
       const row = byExt.get(d.extension) || {
         ext: d.extension, name: d.name,
-        restrict: "none", allowed_numbers: "",
+        restrict: "internal", allowed_numbers: "",
         messaging: false,
       };
       row.ea = true;