Fix a regression from the 1.68->1.69 checkin:

string.split(foo, bar) must be foo.split(bar) instead of bar.split(foo).
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index 2e5cb33..d67a0aa 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -591,7 +591,7 @@
         raise error_proto, resp # should contain '(|||port|)'
     if resp[left + 1] <> resp[right - 1]:
         raise error_proto, resp
-    parts = resp[left+1].split(resp[left + 1:right])
+    parts = resp[left + 1:right].split(resp[left+1])
     if len(parts) <> 5:
         raise error_proto, resp
     host = peer[0]