Update lha command-line to match current *nix and Windows releases of lha

The extraction destination directory must be specified with the 'w=' option.

As Fernando Toledo (@Ragnarok) pointed out:
#524 (comment 4867)

ctrl/sbbsecho.ini

@@ -64,7 +64,7 @@ DefaultRecipient =
 	Sig = 2D6C68
 	SigOffset = 2
 	Pack = lha a %f %s
-	Unpack = lha e %f %s
+	Unpack = lha ew=%s %f
 [archive:ARJ]
 	Sig = 60EA
 	SigOffset = 0