Fix for SF 777848.

I've been bitten by this myself in the past half year.
I hope this fix is right.
I'll backport this to 2.3.

Lib/CGIHTTPServer.py

@@ -177,7 +177,6 @@ class CGIHTTPRequestHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
         if co:
             env['HTTP_COOKIE'] = ', '.join(co)
         # XXX Other HTTP_* headers
-        if not self.have_fork:
         # Since we're setting the env in the parent, provide empty
         # values to override previously set values
         for k in ('QUERY_STRING', 'REMOTE_HOST', 'CONTENT_LENGTH',