fix: handle CMFCore file

The file
`src/Products/CMFCore/tests/fake_skins/fake_skin/test_text_latin1.txt`
in `Products.CMFCore` breaks while trying to read it with a Unicode
error.

Rather than breaking, at least report about it.

z3c/dependencychecker/modules.py

@@ -358,6 +358,12 @@ def create_from_files(cls, top_dir):
                     )
 
     def scan(self):
+        try:
+            yield from self._scan()
+        except UnicodeDecodeError:
+            logger.error("Unicode Problems parsing %s", self.path)
+
+    def _scan(self):
         with open(self.path) as doc_file:
             for line in doc_file:
                 code = self._extract_code(line)