Remove unused uid in pricefeed service

Bisq frequently (once per minute) queries our price nodes for up-to-date
price information. It does so by HTTP GET request. However, it provided
a UID via the "User-Agent" HTTP header field. This UID has been a random
number which changed everytime Bisq got started up.

This UID has never been used. Thus, remove it.

core/src/main/java/bisq/core/provider/price/PriceProvider.java

@@ -48,7 +48,7 @@ public class PriceProvider extends HttpClientProvider {
     public Tuple2<Map<String, Long>, Map<String, MarketPrice>> getAll() throws IOException {
         Map<String, MarketPrice> marketPriceMap = new HashMap<>();
         String json = httpClient.requestWithGET("getAllMarketPrices", "User-Agent", "bisq/"
-                + Version.VERSION + ", uid:" + httpClient.getUid());
+                + Version.VERSION);
 
         LinkedTreeMap<?, ?> map = new Gson().fromJson(json, LinkedTreeMap.class);
         Map<String, Long> tsMap = new HashMap<>();