add shared option for update check

modules/shared.py

@@ -74,6 +74,7 @@ parser.add_argument("--disable-console-progressbars", action='store_true', help=
 parser.add_argument("--enable-console-prompts", action='store_true', help="print prompts to console when generating with txt2img and img2img", default=False)
 parser.add_argument('--vae-path', type=str, help='Path to Variational Autoencoders model', default=None)
 parser.add_argument("--disable-safe-unpickle", action='store_true', help="disable checking pytorch models for malicious code", default=False)
+parser.add_argument("--update-check", action='store_true', help="enable http check to confirm that the currently running version is the most recent release.", default=False)
 
 
 cmd_opts = parser.parse_args()