Fix bamboo build number being empty

[joheintz]

Hi there,
I noticed, that the field git.build.number was empty on our Bamboo (v7.2.3). After a bit of digging, I found that it has to do with the environment variables which the plugin is reading. It's reading bamboo.buildNumber and BAMBOO_BUILDNUMBER, however bamboo is only setting bamboo_buildNumber.
In the documentation (https://confluence.atlassian.com/bamboo/bamboo-variables-289277087.html#Bamboovariables-Systemvariables) under "System variables" it is explained that "Bamboo Variables" are converted to shell variables by converting any dot to an underscore. My understanding is that Bamboo Variables like "bamboo.buildNumber" are only substituted when used in a command or script task in Bamboo.

Contributor Checklist

• Added relevant integration or unit tests to verify the changes
• Update the Readme or any other documentation (including relevant Javadoc)
• Ensured that tests pass locally: mvn clean package
• Ensured that the code meets the current checkstyle coding style definition: mvn clean verify -Pcheckstyle -Dmaven.test.skip=true -B

[TheSnoozer]

Hello,
thank you for your contribution and doing the research where this comes from!
Indeed that sounds like the right place to make this adjustment.

Could you please take a brief look at the comment I left?
Besides that I think this good to be merged.

Thanks again for your contribution!

[TheSnoozer]

Hello,
thank you for your contribution and doing the research where this comes from!
Indeed that sounds like the right place to make this adjustment.

Could you please take a brief look at the comment I left?
Besides that I think this good to be merged.

Thanks again for your contribution!