Gradio Auth Read from External File

Usage: `--gradio-auth-path {PATH}`
It adds the credentials to the already existing `--gradio-auth` credentials. It can also handle line breaks.
The file should look like:
`{u1}:{p1},{u2}:{p2}`
or
```
{u1}:{p1},
{u2}:{p2}
```
Will gradio handle duplicate credentials if it happens?

modules/shared.py

@@ -81,6 +81,7 @@ parser.add_argument("--freeze-settings", action='store_true', help="disable edit
 parser.add_argument("--ui-settings-file", type=str, help="filename to use for ui settings", default=os.path.join(data_path, 'config.json'))
 parser.add_argument("--gradio-debug",  action='store_true', help="launch gradio with --debug option")
 parser.add_argument("--gradio-auth", type=str, help='set gradio authentication like "username:password"; or comma-delimit multiple like "u1:p1,u2:p2,u3:p3"', default=None)
+parser.add_argument("--gradio-auth-path", type=str, help='set gradio authentication file path ex. "/path/to/auth/file" same auth format as --gradio-auth', default=None)
 parser.add_argument("--gradio-img2img-tool", type=str, help='does not do anything')
 parser.add_argument("--gradio-inpaint-tool", type=str, help="does not do anything")
 parser.add_argument("--opt-channelslast", action='store_true', help="change memory type for stable diffusion to channels last")

webui.py

@@ -205,7 +205,7 @@ def webui():
             ssl_keyfile=cmd_opts.tls_keyfile,
             ssl_certfile=cmd_opts.tls_certfile,
             debug=cmd_opts.gradio_debug,
-            auth=[tuple(cred.split(':')) for cred in cmd_opts.gradio_auth.strip('"').split(',')] if cmd_opts.gradio_auth else None,
+            auth=[tuple(cred.split(':')) for cred in (cmd_opts.gradio_auth.strip('"').replace('\n','').split(',') + (open(cmd_opts.gradio_auth_path, 'r').read().strip().replace('\n','').split(',') if cmd_opts.gradio_auth_path and os.path.exists(cmd_opts.gradio_auth_path) else None))] if cmd_opts.gradio_auth or (cmd_opts.gradio_auth_path and os.path.exists(cmd_opts.gradio_auth_path)) else None,
             inbrowser=cmd_opts.autolaunch,
             prevent_thread_lock=True
         )