fix "marshal data too short" error when running bundle install for the first time

When running "bundle install" for the first time bundler crashed and displayed this error "marshal data too short". I found a bundler issue that referenced the error and recommended changing the ruby gems url from http to https (bundler/bundler#2015). Once the initial install is done it did not matter if the url was http or https. But I was able to reproduce by creating a new gemset with rvm and running "bundle install" again.