Revert "Limit VSL size to 4G-1b"

This reverts commit 95100cd0.

We already had a check that took care of this in an architecture
independent way.

See 452ac521
Closes #1750

include/tbl/params.h

@@ -1494,7 +1494,7 @@ PARAM(
 	/* name */	vsl_space,
 	/* typ */	bytes,
 	/* min */	"1M",
-	/* max */	"4294967295",	// 4G-1
+	/* max */	NULL,
 	/* default */	"80M",
 	/* units */	"bytes",
 	/* flags */	MUST_RESTART,