fix http security leak

src/api.lua

@@ -1,3 +1,4 @@
+local http = core.request_http_api()
 local make_fs = i3.files.gui()
 
 IMPORT("gmatch", "split")
@@ -22,13 +23,13 @@ function i3.register_craft(def)
 	local width, c = 0, 0
 
 	if true_str(def.url) then
-		if not i3.http then
+		if not http then
 			return err(fmt([[i3.register_craft(): Unable to reach %s.
 				No HTTP support for this mod: add it to the `secure.http_mods` or
 				`secure.trusted_mods` setting.]], def.url))
 		end
 
-		i3.http.fetch({url = def.url}, function(result)
+		http.fetch({url = def.url}, function(result)
 			if result.succeeded then
 				local t = core.parse_json(result.data)
 				if is_table(t) then

src/caches.lua

@@ -1,3 +1,4 @@
+local http = core.request_http_api()
 local replacements = {fuel = {}}
 
 IMPORT("maxn", "copy", "insert", "sort", "match", "sub")
@@ -269,13 +270,13 @@ local function init_recipes()
 	resolve_aliases(_select)
 	sort(i3.init_items)
 
-	if i3.http and true_str(i3.export_url) then
+	if http and true_str(i3.export_url) then
 		local post_data = {
 			recipes = i3.recipes_cache,
 			usages  = i3.usages_cache,
 		}
 
-		i3.http.fetch_async {
+		http.fetch_async {
 			url = i3.export_url,
 			post_data = core.write_json(post_data),
 		}