rproxy passes the app the client's AS number and country by default (closes #379)

SWW_WAF_ADD_LOOKUP_HEADERS now defaults to true, so the app gets
X-Client-ASN and X-Client-Country with no setting. While
SWW_WAF_LOOKUP_SOURCE is off it defaults to false, so turning lookups
off alone still starts; true set with the lookup off still stops the
start. With GeoJS, a new client's first request now waits for its
answer, up to SWW_WAF_ASN_AND_COUNTRY_LOOKUP_TIMEOUT_MS.

Model: opus-5-5

internal/waf/countries_test.go

@@ -108,8 +108,11 @@ func TestCountryRefusalNamesItsHeuristicCountryAndSetting(t *testing.T) {
 	t.Parallel()
 
 	geojsURL, _ := startGeoJS(t)
+	// The headers are off, so that only the country list makes the request
+	// wait for its answer.
 	s, _, _ := startWithClock(t, geojsURL, map[string]string{
-		asnAndCountryLookupTimeout: "3600000", allowedCountries: "de",
+		asnAndCountryLookupTimeout: "3600000", addLookupHeaders: falseValue,
+		allowedCountries: "de",
 	})
 
 	line := s.get(