fix(main.py): correct key binding and add debug check for render video

croppa/main.py

@@ -1893,7 +1893,7 @@ class VideoEditor:
                 print("  n: Previous video")
             print("  Enter: Render video (overwrites if '_edited_' in name)")
             print("  n: Render video")
-            print("  X: Cancel render")
+            print("  x: Cancel render")
             print("  Q/ESC: Quit")
             print()
 
@@ -2040,7 +2040,7 @@ class VideoEditor:
             elif key == ord("n"):
                 if len(self.video_files) > 1:
                     self.next_video()
-                else:
+            elif key == ord("m"):
                 directory = self.video_path.parent
                 base_name = self.video_path.stem
                 extension = self.video_path.suffix