CFE-4483: Updated syntax description to include new protocol_version values

[nickanderson]

This changes the syntax description for the protocol_version attributes to
include the new version 4/filestream protocol. This change is necessary for the
generated documentation to reflect the current state.

Ticket: CFE-4483
Changelog: Title

[basvandervlies]

Does this also solves this;

07:50 hpcv01p:~/bas/cf_masterfiles/working (update/rm_protocol)
root# cf-agent -IK -f ./update.cf 
/root/bas/cf_masterfiles/working/./lib/update/body.cf:30:28: error: Selection is out of bounds
    protocol_version => "4";
```                           ^

[olehermanse]

@cf-bottom jenkins, please

[cf-bottom]

Sure, I triggered a build:

Jenkins: https://ci.cfengine.com/job/pr-pipeline/11617/

Packages: http://buildcache.cfengine.com/packages/testing-pr/jenkins-pr-pipeline-11617/

[nickanderson]

Does this also solves this;

07:50 hpcv01p:~/bas/cf_masterfiles/working (update/rm_protocol)
root# cf-agent -IK -f ./update.cf 
/root/bas/cf_masterfiles/working/./lib/update/body.cf:30:28: error: Selection is out of bounds
    protocol_version => "4";
```                           ^

Yes, i believe it does:

Prior to the fix:

root@hub:~# cat t.cf
body common control
{
  protocol_version => "4";
}
bundle agent main
{
}


root@hub:~# cf-agent -KIf ./t.cf 
./t.cf:3:26: error: Selection is out of bounds
  protocol_version => "4";
                         ^
   error: There are syntax errors in policy files
   error: Policy failed validation with command '"/var/cfengine/bin/cf-promises" -c "./t.cf"'
   error: Failsafe condition triggered. Interactive session detected, skipping failsafe.cf execution.
   error: Error reading CFEngine policy. Exiting...
root@hub:~# cf-agent --version
CFEngine Core 3.25.0
CFEngine Enterprise 3.25.0

After the fix (using the packages built in the PR):

root@host001:~# cf-agent -KIf ./t.cf 
root@host001:~# cat t.cf 
body common control
{
  protocol_version => "4";
}
bundle agent main
{
}
root@host001:~# cf-agent --version
CFEngine Core 3.26.0a.decd3ad8e
CFEngine Enterprise 3.26.0a.4a27a1555

[nickanderson]

No cherry pick because protocol 4 doesn't exist until 3.25.0 and later and 3.25.0 being a non-lts release there will be no patch versions released.