Update license header template for 2022

[brenuart]

The license template expects the copyright year to be 2021 - it should be updated to expect 2022 instead.

[brenuart]

Also check why the license header is specified in two places:

• once in the license plugin (ok)
• a second time in the checkstyle configuration (why?)

[brenuart]

@philsttr Do you remember any reason why the license header is also enforced by checkstyle in addition to the license maven plugin? It looks like a left over from before we introduced the license plugin and relied solely on checkstyle...

[philsttr]

I believe it is a leftover.

[brenuart]

Ok. I disabled the check from checkstyle.

@philsttr Another remark: if I'm not updating the files, the license header says the copyright applies from 2013 up to 2021. Does it mean that the files were not "protected" in January and February 2022? I mean wouldn't it be better to use an "open range" for the year - or even avoid including a year?
I don't know... I have no problem with updating all files to increment the date once a year. Just wondering what would happen if the project is "dormant" for a long period of time ;-)

[philsttr]

I'm not a lawyer, but I believe they are still protected as long as they aren't changed. I think technically the year only needs to be updated if they are changed. But we can mass-update them if it helps our automation.