Fixes iota unexpected behaviour with bytes for chunk encoding. (#2945)

* Fixes iota unexpected behaviour with bytes for chunk encoding.

This was introducing incompatibilities since iota with bytes starts at 2.
Seems like a weird conversion between iota int and byte.

This can currenlty corrupt chunks, and previous chunks are not decodable.

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

* With iota correclty this time.

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

pkg/chunkenc/memchunk.go

@@ -24,13 +24,13 @@ import (
 )
 
 const (
-	blocksPerChunk = 10
-	maxLineLength  = 1024 * 1024 * 1024
-
 	_ byte = iota
 	chunkFormatV1
 	chunkFormatV2
 	chunkFormatV3
+
+	blocksPerChunk = 10
+	maxLineLength  = 1024 * 1024 * 1024
 )
 
 var (