Main branch broken due to handling user-defined imports #2990

[ERROR] Failures:
[ERROR] org.mapstruct.ap.test.bugs._2897.Issue2897Test.shouldImportNestedClassInMapperImports
[ERROR]   Run 1: Issue2897Test.shouldImportNestedClassInMapperImports [Expected checkstyle compliant output, but got errors:
[ERROR] C:\Programmeren\github\mapstruct\processor\target\compilation-tests\org.mapstruct.ap.test.bugs._2897.Issue2897Test\shouldImportNestedClassInMapperImports_jdk\generated-sources\org\mapstruct\ap\test\bugs\_2897\Issue2897MapperImpl.java:4:8: Nicht verwendeter Import - org.mapstruct.ap.test.bugs._2897.util.Util. [UnusedImports]
]
Expecting:
 <true>
to be equal to:
 <false>
but was not.
[ERROR]   Run 2: Issue2897Test.shouldImportNestedClassInMapperImports [Expected checkstyle compliant output, but got errors:
[ERROR] C:\Programmeren\github\mapstruct\processor\target\compilation-tests\org.mapstruct.ap.test.bugs._2897.Issue2897Test\shouldImportNestedClassInMapperImports_eclipse\generated-sources\org\mapstruct\ap\test\bugs\_2897\Issue2897MapperImpl.java:4:8: Nicht verwendeter Import - org.mapstruct.ap.test.bugs._2897.util.Util. [UnusedImports]
]
Expecting:
 <true>
to be equal to:
 <false>
but was not.