Step 7 of 'Add a key pair' instructs end users to respond to the prompt
to download but Horizon now automatically download Key pair and no
prompt to download the key pair is displayed and moving a section of
code that should reside in 'Add a Key pair'.
This patch updates the doc correctly.
Change-Id: Ic96de6983c7d95c4eca19ae0b6e3d1c700aac9b5
Closes-Bug: #1804139