When indexing a git repo, if a file is copied from an excluded part of the repository, it's line count will not be determined correctly

If indexing a git repository with rename/copy tracking enabled, if a file is copied/moved from a directory that's excluded, the line count of the file won't be determined correctly, potentially causing an extra trip to the repository when doing linecount calculation, to get the actual blame.

HTR:

• see GitFE5660MissingBlameAfterMergeWithAncestryFromExcludedTest - ba84ee is a copy from an excluded path. In GitScanner.processCopyMove() we assume the ancestorLineCount is 0, which is incorrect and causes the wrong linecount to be determined for the file.