diff -ru -x '*~' firefox-55.0.3-orig/docshell/base/nsAboutRedirector.cpp firefox-55.0.3/docshell/base/nsAboutRedirector.cpp
--- firefox-55.0.3-orig/docshell/base/nsAboutRedirector.cpp	2017-07-31 18:20:51.000000000 +0200
+++ firefox-55.0.3/docshell/base/nsAboutRedirector.cpp	2017-09-26 22:02:00.814151731 +0200
@@ -36,10 +36,6 @@
     nsIAboutModule::ALLOW_SCRIPT
   },
   {
-    "buildconfig", "chrome://global/content/buildconfig.html",
-    nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT
-  },
-  {
     "checkerboard", "chrome://global/content/aboutCheckerboard.xhtml",
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |
       nsIAboutModule::ALLOW_SCRIPT
diff -ru -x '*~' firefox-55.0.3-orig/toolkit/content/jar.mn firefox-55.0.3/toolkit/content/jar.mn
--- firefox-55.0.3-orig/toolkit/content/jar.mn	2017-07-31 18:20:52.000000000 +0200
+++ firefox-55.0.3/toolkit/content/jar.mn	2017-09-26 22:01:42.383350314 +0200
@@ -40,7 +40,6 @@
    content/global/plugins.css
    content/global/browser-child.js
    content/global/browser-content.js
-*   content/global/buildconfig.html
    content/global/buildconfig.css
    content/global/contentAreaUtils.js
    content/global/datepicker.xhtml