r935: Unnecessary line in py-buffer-name-prepare

r935 solves the temp-file name problem caused by the ":" character under Windows by replacing it with the "-"character in py-execute-base. It also replaces the ":" character in the buffer name in function py-buffer-name-prepare (line 6709). It doesn't need to do both, and since the buffer name can contain any characters (plus the buffer name looks odd with a "-" character in the middle...), I'd suggest just deleting line 6709,

(setq erg (replace-regexp-in-string ":" "-" erg))