Fix warnings and typos which was detected at #1356 and #1360

[speckyspooky]

Fix warnings and typos which was detected at #1356 and #1360

[speckyspooky]

@wimjongman & @merks
Hello guys, I created that PR to fix some java-warnings of my last changes.
The build process stopped at the start of the "Maven build"-steps because there seems to be a dependency missing.

Have you an idea how we can fix it - rerun was stopped with the same error:

Error: Failed to resolve target definition file:/home/runner/work/birt/birt/build/org.eclipse.birt.target/org.eclipse.birt.target.target: Could not find "org.eclipse.mylyn.bugzilla_feature.feature.group/0.0.0" in the repositories of the current location -> [Help 1]

[merks]

Mylyn has been changing the IDs of most of its features. I'll need to make updates accordingly.

[speckyspooky]

Thanks of your fast investigation

[merks]

The build with the update target platform was successful so I updated the branch of this PR...