Bug fix: export alignement.json file with save-interval option.
diff --git a/scripts/extract.py b/scripts/extract.py
index 4f81ef7f12..4ca7e32489 100644
--- a/scripts/extract.py
+++ b/scripts/extract.py
@@ -191,7 +191,7 @@ def run_extraction(self):
                 if self.extractor.final_pass:
                     self.output_processing(faces, align_eyes, size, filename)
                     self.output_faces(filename, faces)
-                    if self.save_interval and idx + 1 % self.save_interval == 0:
+                    if self.save_interval and (idx + 1) % self.save_interval == 0:
                         self.alignments.save()
                 else:
                     del faces["image"]

One-liner fix. The modulo operation has priority over the addition. Because parentheses were missing in the condition, the condition was never met. Because of this, even if we run the extract script with the `save-interval` option, the alignements.json file is never generated.

Fixes https://github.com/deepfakes/faceswap/issues/739