Rework the TestProxyClose - close the proxy in the *same* goroutine
as where we started it. Close channels as long as we don't get dataraces
(this may need another fix).
Move the Dial goroutine out of the connManager - this simplifies things
*and* makes another goroutine go away and removes the need for connErr
channels - can now just be dns.Conn.
Also:
Revert "plugin/forward: gracefull stop (#1701)"
This reverts commit 135377bf776295d8ef86081c1ef581e7b41d26f0.
Revert "rework TestProxyClose (#1735)"
This reverts commit 9e8893a0b5325a76b2784958bbe743ff3e831401.