add muescha's bug catch: error checking for download archive url
add muescha's bug catch: error checking for download archive url

thepatrick/Opentok-Ruby-SDK,brando10/Opentok-Ruby-SDK,mpaniotov/Opentok-Ruby-SDK,aoberoi/Opentok-Ruby-SDK,HomeStayTravel/Opentok-Ruby-SDK,HomeStayTravel/Opentok-Ruby-SDK,thepatrick/Opentok-Ruby-SDK,mpaniotov/Opentok-Ruby-SDK,opentok/Opentok-Ruby-SDK,HomeStayTravel/Opentok-Ruby-SDK,thepatrick/Opentok-Ruby-SDK,opentok/Opentok-Ruby-SDK,mpaniotov/Opentok-Ruby-SDK,opentok/Opentok-Ruby-SDK,aoberoi/Opentok-Ruby-SDK,brando10/Opentok-Ruby-SDK,brando10/Opentok-Ruby-SDK