[source] Set up logging correctly in all cases
[source] Set up logging correctly in all cases

Set up logging correctly:
- in datadog.conf when the file exists or is created by the script
- in datadog.conf.example otherwise

[skip ci]

pmav99/praktoras,brettlangdon/dd-agent,Wattpad/dd-agent,tebriel/dd-agent,Wattpad/dd-agent,c960657/dd-agent,lookout/dd-agent,tebriel/dd-agent,Wattpad/dd-agent,takus/dd-agent,indeedops/dd-agent,Wattpad/dd-agent,jyogi/purvar-agent,cberry777/dd-agent,gphat/dd-agent,indeedops/dd-agent,manolama/dd-agent,gphat/dd-agent,brettlangdon/dd-agent,tebriel/dd-agent,manolama/dd-agent,pmav99/praktoras,c960657/dd-agent,tebriel/dd-agent,cberry777/dd-agent,cberry777/dd-agent,cberry777/dd-agent,c960657/dd-agent,jyogi/purvar-agent,tebriel/dd-agent,manolama/dd-agent,lookout/dd-agent,takus/dd-agent,manolama/dd-agent,lookout/dd-agent,pmav99/praktoras,brettlangdon/dd-agent,gphat/dd-agent,cberry777/dd-agent,c960657/dd-agent,indeedops/dd-agent,brettlangdon/dd-agent,c960657/dd-agent,takus/dd-agent,Wattpad/dd-agent,gphat/dd-agent,indeedops/dd-agent,takus/dd-agent,takus/dd-agent,gphat/dd-agent,jyogi/purvar-agent,jyogi/purvar-agent,lookout/dd-agent,indeedops/dd-agent,lookout/dd-agent,jyogi/purvar-agent,brettlangdon/dd-agent,pmav99/praktoras,manolama/dd-agent,pmav99/praktoras