Bug 1843763 - Stop using nsGIOProtocolHandler for sftp by default r=necko-reviewers,jesup

nsGIOProtocolHandler is a linux specific protocol handler that deals with a
set of linux specific schemes https://wiki.gnome.org/Projects/gvfs/schemes

One of these is the sftp protocol. Since we now allow
navigator.registerProtocolHandler for "sftp", it should no longer be
registered by default by the gio protocol handler.

Differential Revision: https://phabricator.services.mozilla.com/D185539

netwerk/protocol/gio/nsGIOProtocolHandler.cpp

@@ -890,12 +890,7 @@ void nsGIOProtocolHandler::InitSupportedProtocolsPref(nsIPrefBranch* prefs) {
     prefValue.StripWhitespace();
     ToLowerCase(prefValue);
   } else {
-    prefValue.AssignLiteral(
+    prefValue.AssignLiteral(""  // use none by default
-#ifdef MOZ_PROXY_BYPASS_PROTECTION
-        ""  // use none
-#else
-        "sftp:"  // use defaults (comma separated list)
-#endif
     );
   }
   LOG(("gio: supported protocols \"%s\"\n", prefValue.get()));

testing/web-platform/meta/html/webappapis/system-state-and-capabilities/the-navigator-object/protocol.https.html.ini

@@ -1,8 +1,4 @@
 [protocol.https.html]
-  expected:
-    if os == "linux": CRASH
-  disabled:
-    if asan: https://bugzilla.mozilla.org/show_bug.cgi?id=1841488
   [the unregisterProtocolHandler method should exist on the navigator object]
     expected: FAIL