Do not use unnecessary lock in connRewind

mtglib/conns.go

 	"bytes"
 	"context"
 	"io"
-	"sync"
 
 	"github.com/9seconds/mtg/v2/essentials"
 )
 type connRewind struct {
 	essentials.Conn
 
-	active io.Reader
 	buf    bytes.Buffer
-	mutex  sync.RWMutex
+	active io.Reader
 }
 
 func (c *connRewind) Read(p []byte) (int, error) {
-	c.mutex.RLock()
-	defer c.mutex.RUnlock()
-
-	return c.active.Read(p) //nolint: wrapcheck
+	return c.active.Read(p)
 }
 
 func (c *connRewind) Rewind() {
-	c.mutex.Lock()
-	defer c.mutex.Unlock()
-
 	c.active = io.MultiReader(&c.buf, c.Conn)
 }
 

mtglib/proxy.go

 		return fmt.Errorf("no addresses to call: %w", err)
 	}
 
-	conn, err = foundAddr.Obfuscator.SendHandshake(conn, ctx.dc)
+	tgConn, err := foundAddr.Obfuscator.SendHandshake(conn, ctx.dc)
 	if err != nil {
 		conn.Close()
 		return fmt.Errorf("cannot perform server handshake: %w", err)
 	}
 
 	ctx.telegramConn = connTraffic{
-		Conn:     conn,
+		Conn:     tgConn,
 		streamID: ctx.streamID,
 		stream:   p.eventStream,
 		ctx:      ctx,