Close file in Kilo after save

If file isn't closed, changes don't persist. Noticed when testing file creation/editing on SD card.

Author: atfox98

src/kilo/kilo.cpp

@@ -1010,6 +1010,7 @@ namespace ESP32Console::Kilo
 
  close(fd);*/
  free(buf);
+ fclose(file);
  E.dirty = 0;
  editorSetStatusMessage("%d bytes written on disk", len);
  return 0;