REG-TESTS: stickiness: Delay haproxys start to properly resolv variables

REG-TESTS: stickiness: Delay haproxys start to properly resolv variables

Because of the commit 5cb8d7b8f ("BUG/MINOR: peers: Improve detection of
config errors in peers sections"), 2 scripts now report errors during
startup because some variables are not set and the remote peer server is
thus malformed. To perform a peer synchro between 2 haproxys in these
scripts, the startup must be delayed to properly resolve addresses.

In addidiotn, we must wait (2s) to be sure the connection between peers is
properly established. These scripts are now flagged as slow.