Log field sshv and csshv take 16 bytes for each

[maskit]

Both sshv and csshv store just an HTTP version, the major version and the minor version. The type of those fields is dINT (double int) somehow. A 64 bit integer for the major version and another 64 bit integer for the minor version.

We should change the type to STRING and use just 1 byte (or 2 bytes at maximum). Even sINT (64 bit integer) is too much.

This change would cause log format incompatibility.