Revert socket buffer default to fix performance issues.

Author: chernser

client-v2/src/main/java/com/clickhouse/client/api/ClientConfigProperties.java

@@ -52,9 +52,9 @@ public enum ClientConfigProperties {
 
     SOCKET_OPERATION_TIMEOUT("socket_timeout", "0"),
 
-    SOCKET_RCVBUF_OPT("socket_rcvbuf", "8196"),
+    SOCKET_RCVBUF_OPT("socket_rcvbuf", "804800"),
 
-    SOCKET_SNDBUF_OPT("socket_sndbuf", "8196"),
+    SOCKET_SNDBUF_OPT("socket_sndbuf", "804800"),
 
     SOCKET_REUSEADDR_OPT("socket_reuseaddr"),