Deactivate curl progress bar by default for fetching roles

It is safer to deactivate that progress bar by default, as
it can trigger to JavaHeap overflow during Jenkins tests.

Using PB=1 as envrironment variable enable the progress bar.

Change-Id: If5ddae20aaf6c18ef4f50e8fda1066c58cb493a9
Merge "Deactivate curl progress bar by default for fetching roles"