[Pale-Moon] Issue #1845 - Pref detach&tear-off tab handling.

Resolves #1845

application/palemoon/base/content/tabbrowser.xml

@@ -4831,6 +4831,11 @@
           return;
         }
 
+        // Check if tab detaching is enabled
+        if (!Services.prefs.getBoolPref("browser.tabs.allowTabDetach")) {
+          return;
+        }
+
         // Disable detach within the browser toolbox
         var eX = event.screenX;
         var eY = event.screenY;