Update rscons

Rsconscript

@@ -3,8 +3,7 @@ configure do
   check_program "x86_64-w64-mingw32-gcc"
 end
 
-build do
+class Image < Builder
-  class Image < Builder
   def run(options)
     unless @cache.up_to_date?(@target, nil, @sources, @env)
       print_run_message("Image <target>#{@target}<reset>", nil)
@@ -17,8 +16,9 @@ build do
     end
     true
   end
-  end
+end
-  Environment.new do |env|
+
+env do |env|
   env.add_builder(Image)
   env["CC"] = "x86_64-w64-mingw32-gcc"
   env["CPPPATH"] += %w[/usr/include/efi /usr/include/efi/x86_64]
@@ -28,5 +28,4 @@ build do
   env["sources"] = glob("*.c")
   env.Program("^/BOOTX64.EFI", "${sources}")
   env.Image("^/efi-loader.img", "^/BOOTX64.EFI")
-  end
 end