fix(modulefinder): use subpath instead of relative_path in fscache.isdir check in matches_gitignore

Author: ferkans-amir

mypy/modulefinder.py

@@ -711,7 +711,7 @@ def matches_gitignore(subpath: str, fscache: FileSystemCache, verbose: bool) ->
     dir, _ = os.path.split(subpath)
     for gi_path, gi_spec in find_gitignores(dir):
         relative_path = os.path.relpath(subpath, gi_path)
-        if fscache.isdir(relative_path):
+        if fscache.isdir(subpath):
             relative_path = relative_path + "/"
         if gi_spec.match_file(relative_path):
             if verbose: