doc: Reorder protocol version option descriptions in libpq docs.

doc: Reorder protocol version option descriptions in libpq docs.

Commit 285613c60a7 introduced the min_protocol_version and
max_protocol_version connection options for libpq, but their descriptions
were placed in the middle of the unrelated ssl_min_protocol_version and
ssl_max_protocol_version entries.

This commit moves the min_protocol_version and max_protocol_version
descriptions to appear after the SSL-related options. This improves
the logical order and makes it easier for users to locate the relevant
settings in the libpq documentation.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Discussion: https://postgr.es/m/a3391f36-30f5-4d4a-825b-232476819de8@oss.nttdata.com