No files to analyze could be opened

[Wuaner]

For a merge commit that no java file involved, belowing exception will throwed:

There is a problem with FindBugs: IOException: No files to analyze could be opened.

I think if it's a better idea that not throw exception for this scenario, because this is pretty normal situation for merge commit.

[AlanHohn]

This seems to have come in when support was added for global problems collection (https://github.com/TouK/sputnik/commit/75b30e12a1ec6378eaa29853dc539e50ea7bd37d). The previous behavior was to suppress an IOException.

Not sure if there are downsides to suppressing IOException (i.e. real errors from Findbugs) but it sure is annoying to have it posting this "problem" report when it shouldn't. I'm happy to submit a pull request to put the previous behavior back - worth a discussion at least.