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/proxy_test.go

@@ -93,6 +93,10 @@ const off = "off"
 // on is the value that switches a setting that takes true or false on.
 const on = "true"
 
+// falseValue is the value that switches a setting that takes true or false
+// off.
+const falseValue = "false"
+
 // output collects what sww writes on stdout.
 type output struct {
 	mu  sync.Mutex