Remove incompatible server version direct stdout (#1032)

Author: jkaflik

conn.go

@@ -102,8 +102,6 @@ func dial(ctx context.Context, addr string, num int, opt *Options) (*connect, er
 
 	// warn only on the first connection in the pool
 	if num == 1 && !resources.ClientMeta.IsSupportedClickHouseVersion(connect.server.Version) {
-		// send to debugger and console
-		fmt.Printf("WARNING: version %v of ClickHouse is not supported by this client\n", connect.server.Version)
 		debugf("[handshake] WARNING: version %v of ClickHouse is not supported by this client - client supports %v", connect.server.Version, resources.ClientMeta.SupportedVersions())
 	}
 	return connect, nil

conn_http.go

@@ -27,10 +27,12 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"log"
 	"mime/multipart"
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -136,6 +138,15 @@ func (rw *HTTPReaderWriter) reset(pw *io.PipeWriter) io.WriteCloser {
 }
 
 func dialHttp(ctx context.Context, addr string, num int, opt *Options) (*httpConnect, error) {
+	var debugf = func(format string, v ...any) {}
+	if opt.Debug {
+		if opt.Debugf != nil {
+			debugf = opt.Debugf
+		} else {
+			debugf = log.New(os.Stdout, fmt.Sprintf("[clickhouse][conn=%d][%s]", num, addr), 0).Printf
+		}
+	}
+
 	if opt.scheme == "" {
 		switch opt.Protocol {
 		case HTTP:
@@ -239,7 +250,7 @@ func dialHttp(ctx context.Context, addr string, num int, opt *Options) (*httpCon
 			return nil, err
 		}
 		if !resources.ClientMeta.IsSupportedClickHouseVersion(version) {
-			fmt.Printf("WARNING: version %v of ClickHouse is not supported by this client\n", version)
+			debugf("WARNING: version %v of ClickHouse is not supported by this client\n", version)
 		}
 	}