Move setsid(1) to toybox.

Test: treehugger
Change-Id: I8caf9dbbb671218379c309e698f23e7c964f1a18
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index 89d012e..db2e3bb 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -126,7 +126,6 @@
 	"rm":        Allowed,
 	"rsync":     Allowed,
 	"sed":       Allowed,
-	"setsid":    Allowed,
 	"sh":        Allowed,
 	"sha1sum":   Allowed,
 	"sha256sum": Allowed,
@@ -170,6 +169,7 @@
 	"paste":  Toybox,
 	"pwd":    Toybox,
 	"rmdir":  Toybox,
+	"setsid": Toybox,
 	"sleep":  Toybox,
 	"tail":   Toybox,
 	"tee":    Toybox,