';' in resolv.conf also means comment

Skip ';'-prefixed lines in /etc/resolv.conf as well.

core/pkg/net/dns/dns.go

@@ -38,7 +38,7 @@ func GetSystemNameServers() ([]net.IP, error) {
 	lines := strings.Split(string(file), "\n")
 	for l := range lines {
 		trimmed := strings.TrimSpace(lines[l])
-		if strings.HasPrefix(trimmed, "#") {
+		if len(trimmed) == 0 || trimmed[0] == '#' || trimmed[0] == ';' {
 			continue
 		}
 		fields := strings.Fields(trimmed)

core/pkg/net/dns/dns_test.go

@@ -40,6 +40,8 @@ func TestGetDNSServers(t *testing.T) {
 	defer os.Remove(file.Name())
 
 	ioutil.WriteFile(file.Name(), []byte(`
+	# comment
+	; comment
 	nameserver 2001:4860:4860::8844
 	nameserver 2001:4860:4860::8888
 	nameserver 8.8.8.8