Bug 1888383: Update tests within testing/mochitest/tests/Harness_sanity/ to work with https-first enabled, r=ahal

Differential Revision: https://phabricator.services.mozilla.com/D206000

testing/mochitest/tests/Harness_sanity/xpcshell.toml

@@ -1,5 +1,7 @@
 [DEFAULT]
 
 ["test_SpecialPowersSandbox.js"]
+prefs = ["dom.security.https_first=false"] #Disable https-first because createHttpServer does not support https
 
 ["test_SpecialPowersSpawn.js"]
+prefs = ["dom.security.https_first=false"] #Disable https-first because createHttpServer does not support https