tests: explicit tunnel version URI in sauce_tunnel.sh
tests: explicit tunnel version URI in sauce_tunnel.sh

For an explanation, see bf0bb58c703f.

ether/etherpad-lite,ether/etherpad-lite,storytouch/etherpad-lite,joequant/etherpad-lite,storytouch/etherpad-lite,joequant/etherpad-lite,ether/etherpad-lite,joequant/etherpad-lite,aptivate/etherpad-lite,aptivate/etherpad-lite,storytouch/etherpad-lite,aptivate/etherpad-lite,joequant/etherpad-lite,aptivate/etherpad-lite