Disable response compression on /git-receive-pack URLs
Compressing the response with gzip causes the stream to delay
flushing until gzip has seen the entire response message, or buffers
fill up and the compressed data has to be sent. This hides the
resolving progress monitor from the client, as well as any other
progress messages the server might be trying to send.
Disable compression in receive, matching what /git-upload-pack has.