Fixed incorrect use of r->http_version in scgi module. The r->http_version is a version of client's request, and modules must not set it unless they are really willing to downgrade protocol version used for a response (i.e. to HTTP/0.9 if no response headers are available). In neither case r->http_version may be upgraded. The former code downgraded response from HTTP/1.1 to HTTP/1.0 for no reason, causing various problems (see ticket #66). It was also possible that HTTP/0.9 requests were upgraded to HTTP/1.0.