t4205: replace .\+ with ..* in sed commands

OS X's sed only accepts basic regular expressions, which does not
allow the + quantifier.  However '..*' (anything, followed by zero or
more anything) is the same as '.\+' (one or more anything) and valid
in any regular expression language.

Signed-off-by: Brian Gernhardt <brian@gernhardtsoftware.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>