test_all: run the 50 byte chunker tests against Minio instead of AWS S3

The 5 chunker remotes with 50 byte chunks split each test file into
many objects which made them expensive to run against AWS S3. Run
them against the TestS3Minio docker server instead and keep
TestChunkerS3 with the default chunk size on AWS.

fs/sync/sync_test.go

@@ -1677,8 +1677,8 @@ func TestSyncWithTrackRenamesStrategyLeaf(t *testing.T) {
 func toyFileTransfers(r *fstest.Run) int64 {
 	remote := r.Fremote.Name()
 	transfers := 1
-	if strings.HasPrefix(remote, "TestChunker") && strings.HasSuffix(remote, "S3") {
-		transfers++ // Extra Copy because S3 emulates Move as Copy+Delete.
+	if unWrap := r.Fremote.Features().UnWrap; strings.HasPrefix(remote, "TestChunker") && unWrap != nil && unWrap().Features().Move == nil {
+		transfers++ // Extra Copy because chunker emulates Move as Copy+Delete.
 	}
 	return int64(transfers)
 }

fstest/test_all/config.yaml

@@ -84,15 +84,15 @@ backends:
    remote:   "TestChunkerS3:"
    fastlist: true
  - backend:  "chunker"
-   remote:   "TestChunkerChunk50bS3:"
+   remote:   "TestChunkerChunk50bMinio:"
    fastlist: true
    maxfile:  1k
  - backend:  "chunker"
-   remote:   "TestChunkerChunk50bMD5HashS3:"
+   remote:   "TestChunkerChunk50bMD5HashMinio:"
    fastlist: true
    maxfile:  1k
  - backend:  "chunker"
-   remote:   "TestChunkerChunk50bSHA1HashS3:"
+   remote:   "TestChunkerChunk50bSHA1HashMinio:"
    fastlist: true
    maxfile:  1k
  - backend:  "chunker"
@@ -100,11 +100,11 @@ backends:
    fastlist: true
    maxfile:  6k
  - backend:  "chunker"
-   remote:   "TestChunkerChunk50bMD5QuickS3:"
+   remote:   "TestChunkerChunk50bMD5QuickMinio:"
    fastlist: true
    maxfile:  1k
  - backend:  "chunker"
-   remote:   "TestChunkerChunk50bSHA1QuickS3:"
+   remote:   "TestChunkerChunk50bSHA1QuickMinio:"
    fastlist: true
    maxfile:  1k
  ## end chunker