If set, a server configured to accept leafnode connections will
reject a remote server whose version is below that value. Note
that servers prior to v2.8.0 are not sending their version
in the CONNECT protocol, which means that anything below 2.8.0
would be rejected.
Configuration example:
```
leafnodes {
port: 7422
min_version: 2.8.0
}
```
The option is a string and can have the "v" prefix:
```
min_version: "v2.9.1"
```
Note that although suffix such as `-beta` would be accepted,
only the major, minor and update are used for the version comparison.
Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
9e6f965913