Update Rakefile

Author: Asmod4n

Rakefile

@@ -1,7 +1,8 @@
 MRUBY_CONFIG=File.expand_path(ENV["MRUBY_CONFIG"] || "build_config.rb")
 
 file :mruby do
-  sh "git clone --recursive --depth=1 https://github.com/mruby/mruby.git"
+  sh "git clone --recurse-submodules --depth=1 https://github.com/mruby/mruby.git"
+  sh "git submodule update --init --recursive"
 end
 
 desc "compile binary"