overrided addSearchPath() by Runtime.cpp should support second argument as CCFileUtils.cpp does.
Merge pull request #8982 from CocosRobot/update_lua_bindings_1414723317

[AUTO]: updating luabinding automatically
init arg1 as false for safety
Merge pull request #8976 from hongliang-goudou/runtime_addSearchPath_argc

overrided addSearchPath() by Runtime.cpp should support second argument