all: Remove "large blocks" config (#5763)

We now always use large / variable blocks.

lib/config/folderconfiguration.go

@@ -52,7 +52,6 @@ type FolderConfiguration struct {
 	Paused                  bool                        `xml:"paused" json:"paused"`
 	WeakHashThresholdPct    int                         `xml:"weakHashThresholdPct" json:"weakHashThresholdPct"` // Use weak hash if more than X percent of the file has changed. Set to -1 to always use weak hash.
 	MarkerName              string                      `xml:"markerName" json:"markerName"`
-	UseLargeBlocks          bool                        `xml:"useLargeBlocks" json:"useLargeBlocks" default:"true"`
 	CopyOwnershipFromParent bool                        `xml:"copyOwnershipFromParent" json:"copyOwnershipFromParent"`
 
 	cachedFilesystem fs.Filesystem