cmd/tailscale/cli: reduce strength of lose-ssh risk warning

Ideally we would remove this warning entirely, as it is now possible to
reauthenticate without losing connectivty. However, it is still possible to
lose SSH connectivity if the user changes the ownership of the machine when
they do a force-reauth, and we have no way of knowing if they are going to
do that before they do it.

For now, let's just reduce the strength of the warning to warn them that
they "may" lose their connection, rather than they "will".

Updates tailscale/corp#32429

Signed-off-by: James Sanderson <jsanderson@tailscale.com>

cmd/tailscale/cli/up.go

@@ -385,7 +385,7 @@ func updatePrefs(prefs, curPrefs *ipn.Prefs, env upCheckEnv) (simpleUp bool, jus
 	}
 
 	if env.upArgs.forceReauth && isSSHOverTailscale() {
-		if err := presentRiskToUser(riskLoseSSH, `You are connected over Tailscale; this action will result in your SSH session disconnecting.`, env.upArgs.acceptedRisks); err != nil {
+		if err := presentRiskToUser(riskLoseSSH, `You are connected over Tailscale; this action may result in your SSH session disconnecting.`, env.upArgs.acceptedRisks); err != nil {
 			return false, nil, err
 		}
 	}