osbase/net/dns/forward/proxy: make test less flaky

I observed a failure of TestCoreDNSOverflow with a timeout on CI.
It additionally caused a panic because response was nil.

The timeouts were originally set this low to speed up tests, but for
these tests, we don't expect to hit timeouts, so this does not make them
slower.

Change-Id: Ie8bb6d30be6f0cefba7a124f7b49e1e570d7cd10
Reviewed-on: https://review.monogon.dev/c/monogon/+/4043
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
Tested-by: Jenkins CI
diff --git a/osbase/net/dns/forward/proxy/proxy_test.go b/osbase/net/dns/forward/proxy/proxy_test.go
index 4d120a6..70fd6b2 100644
--- a/osbase/net/dns/forward/proxy/proxy_test.go
+++ b/osbase/net/dns/forward/proxy/proxy_test.go
@@ -27,7 +27,6 @@
 	defer s.Close()
 
 	p := NewProxy(s.Addr)
-	p.readTimeout = 10 * time.Millisecond
 	p.Start(5 * time.Second)
 	m := new(dns.Msg)
 
@@ -45,7 +44,6 @@
 
 func TestProtocolSelection(t *testing.T) {
 	p := NewProxy("bad_address")
-	p.readTimeout = 10 * time.Millisecond
 
 	go func() {
 		p.Connect(new(dns.Msg), false)
@@ -106,7 +104,6 @@
 	defer s.Close()
 
 	p := NewProxy(s.Addr)
-	p.readTimeout = 10 * time.Millisecond
 	p.Start(5 * time.Second)
 	defer p.Stop()
 
@@ -120,6 +117,7 @@
 		response, err := p.Connect(queryMsg, useTCP)
 		if err != nil {
 			t.Errorf("Failed to connect to testdnsserver: %s", err)
+			return
 		}
 
 		if response.Truncated != expectTruncated {