Move the flexbox notification into Main.

src/features.coffee

@@ -254,16 +254,6 @@ Settings =
       open: -> Conf['Enable 4chan\'s Extension']
 
     $.get 'previousversion', null, (item) ->
-      <% if (type === 'userscript') { %>
-      el = $.el 'span'
-      el.style.flex = 'test'
-      if el.style.flex is 'test'
-        el.innerHTML = """
-        Firefox is not correctly set up and some <%= meta.name %> features will be displayed incorrectly.<br>
-        Follow the instructions of the <a href='<%= meta.page %>' target=_blank>install guide</a> to fix it.
-        """
-        new Notification 'warning', el, 30
-      <% } %>
       if previous = item['previousversion']
         return if previous is g.VERSION
         # Avoid conflicts between sync'd newer versions

src/main.coffee

@@ -469,6 +469,16 @@ Main =
 
     if $.hasClass d.body, 'fourchan_x'
       alert '4chan X v2 detected: Disable it or v3 will break.'
+    <% if (type === 'userscript') { %>
+    el = $.el 'span'
+    el.style.flex = 'test'
+    if el.style.flex is 'test'
+      el.innerHTML = """
+      Firefox is not correctly set up and some <%= meta.name %> features will be displayed incorrectly.<br>
+      Follow the instructions of the <a href='<%= meta.page %>' target=_blank>install guide</a> to fix it.
+      """
+      new Notification 'warning', el, 30
+    <% } %>
 
     $.event '4chanXInitFinished'
     Main.checkUpdate()