--webcam-size should be 0-100 instead of 0-99

[jmlich]

subject says it all

here is a patch

diff --git a/make-xges.py b/make-xges.py
index 4df2d9d..7aa0593 100755
--- a/make-xges.py
+++ b/make-xges.py
@@ -440,7 +440,7 @@ def main(argv):
     parser.add_argument('--height', metavar='HEIGHT', type=int, default=1080,
                         help='Video height')
     parser.add_argument('--webcam-size', metavar='PERCENT', type=int,
-                        default=25, choices=range(100),
+                        default=25, choices=range(101),
                         help='Amount of screen to reserve for camera')
     parser.add_argument('--stretch-webcam', action='store_true',
                         help='Stretch webcam to 16:9 aspect ratio')