Maven: Skip compilation of source file is artifactId missing

[Mathieu Malaterre <malat@debian.org>]

Hi there,

When building fop, I'd like to skip building the following source file:

./fop-core/src/main/java/org/apache/fop/util/bitmap/JAIMonochromeBitmapConverter.java

Back in the old 'ant' days, this was done by upstream with:

build.xml:    <exclude
name="org/apache/fop/util/bitmap/JAIMonochromeBitmapConverter.java"
unless="jai.present"/>

Since debian does not ship jai-core/jai-imageio-core I'd like to skip
compilation of this file (right now I did a git rm).

Thanks