panic: close of closed channel

goroutine 21 [running]:
github.com/caddyserver/caddy/v2/modules/caddytls.(*TLS).Stop(0x40002ff2c0)
        github.com/caddyserver/caddy/v2@v2.8.4/modules/caddytls/tls.go:338 +0x2c
github.com/caddyserver/caddy/v2.unsyncedStop({{0x1970cc0, 0x4000557b30}, 0x40002b0270, 0x40003c2780, {0x0, 0x0, 0x0}, {0x0, 0x0, 0x0}, ...})                                                                                                            github.com/caddyserver/caddy/v2@v2.8.4/caddy.go:677 +0xcc
github.com/caddyserver/caddy/v2.Stop()
        github.com/caddyserver/caddy/v2@v2.8.4/caddy.go:646 +0x138
github.com/caddyserver/caddy/v2.exitProcess({0x1970c50, 0x26037c0}, 0x4000982300)
        github.com/caddyserver/caddy/v2@v2.8.4/caddy.go:721 +0x248
github.com/caddyserver/caddy/v2.exitProcessFromSignal({0x1443925, 0x7})                                                         github.com/caddyserver/caddy/v2@v2.8.4/sigtrap.go:59 +0xe4
github.com/caddyserver/caddy/v2.trapSignalsPosix.func1()
        github.com/caddyserver/caddy/v2@v2.8.4/sigtrap_posix.go:44 +0x4f8
created by github.com/caddyserver/caddy/v2.trapSignalsPosix in goroutine 1
        github.com/caddyserver/caddy/v2@v2.8.4/sigtrap_posix.go:31 +0x24