bitcoin#15013: test: Avoid race in p2p_timeouts

Has been changed in dash since this commit

fabcd64 test: Avoid racy test p2p_timeouts (MarcoFalke)

Pull request description:

  Avoid filesystem/network racyness by sleeping another second. The alternative would be to poll the `debug.log`, but that seems overkill to avoid a sleep in a test that already requires them.

Tree-SHA512: 32de75ecba38426323158fda241e37ffae73806d8c0e60b7ad73fb917e9cd25a3e5f0722cbc6f2f7a5b86501221c317783266bc2e3b4697fb120f05898ccc12d