Bug 1853548 - Remove dom.no_unknown_protocol_error.enabled pref r=gregp,smaug

Differential Revision: https://phabricator.services.mozilla.com/D210862

docshell/base/nsDocShell.cpp

@@ -6151,7 +6151,6 @@ nsresult nsDocShell::FilterStatusForErrorPage(
     // to see the error page.
     nsCOMPtr<nsILoadInfo> info = aChannel->LoadInfo();
     if (!info->TriggeringPrincipal()->IsSystemPrincipal() &&
-        StaticPrefs::dom_no_unknown_protocol_error_enabled() &&
         !aIsInitialDocument) {
       if (aSkippedUnknownProtocolNavigation) {
         *aSkippedUnknownProtocolNavigation = true;

modules/libpref/init/StaticPrefList.yaml

@@ -3218,13 +3218,6 @@
   value: true
   mirror: always
 
-# Whether we shouldn't show an error page for unknown protocols (and should
-# show a console warning instead).
-- name: dom.no_unknown_protocol_error.enabled
-  type: bool
-  value: true
-  mirror: always
-
 # Whether origin trials are enabled.
 - name: dom.origin-trials.enabled
   type: bool