Add method for creating empty atomic strings

src/github.com/getlantern/flashlight/geolookup/geolookup.go

@@ -31,10 +31,16 @@ var (
 	service  *ui.Service
 	client   atomic.Value
 	cfgMutex sync.Mutex
-	country  atomic.Value
-	ip       atomic.Value
+	country  = atomicString()
+	ip       = atomicString()
 )
 
+func atomicString() atomic.Value {
+	var val atomic.Value
+	val.Store("")
+	return val
+}
+
 func GetIp() string {
 	return ip.Load().(string)
 }