set keepAliveLimit if HTTP 1.1
don't subtract 2 seconds from keepAliveLimit

keepAliveLimit+=timeout is already a conservative value, as the client set keepAliveLimit to a moment in time before the request was transmitted. So without subtracting 2s, the client's notion of connection timeout will be before the server's notion of it.
Revert "don't subtract 2 seconds from keepAliveLimit"

This reverts commit e9eef52350c7dbf570cf981c77b3afe257836d20.
Merge pull request #450 from gittywithexcitement/keepAlive

Assume keep alive if no "Connection: close" header is present.