Update bclargs.py

> ./bclargs.py -s 
usage: bclargs.py [-h] [--render-anim] [--background] [--window-border]
                  [--window-borderless] [--start-console] [--no-native-pixels]
                  [--scene SCENE] [--frame-start FRAME_START]
                  [--frame-end FRAME_END] [--frame-jump FRAME_JUMP]
                  [--window-geometry WINDOW_GEOMETRY WINDOW_GEOMETRY WINDOW_GEOMETRY WINDOW_GEOMETRY]
bclargs.py: error: argument --frame-start/-s: expected one argument


> ./bclargs.py -b -s 1 -e 56 -j 3 -S AnimLayout -a
Namespace(background=True, frame_end=56, frame_jump=3, frame_start=1, no_native_pixels=False, render_anim=True, scene='AnimLayout', start_console=False, window_border=False, window_borderless=False, window_geometry=None)