[demos/lint-history] Fix single quotes in single quotes

Signed-off-by: Alexander Georgievskiy <galeksandrp@gmail.com>

contrib/filter-repo-demos/lint-history

@@ -31,7 +31,7 @@ near the top of git-filter-repo.
 # about filenames, then this program could be replaced by a "one-liner"; e.g.
 #    git filter-repo --force --blob-callback '
 #      if not b"\0" in blob.data[0:8192]:
-#        filename = '.git/info/tmpfile'
+#        filename = ".git/info/tmpfile"
 #        with open(filename, "wb") as f:
 #          f.write(blob.data)
 #        subprocess.check_call(["lint_program", "--some", "arg", filename])