[stripchat] url support for special symbols "@"

[ghost]

Checklist

• I'm reporting a broken site
• I've verified that I'm running yt-dlp version 2022.07.18 (update instructions) or later (specify commit)
• I've checked that all provided URLs are playable in a browser with the same IP and same login details
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar issues including closed ones. DO NOT post duplicates
• I've read the guidelines for opening an issue
• I've read about sharing account credentials and I'm willing to share it if required

Region

No response

Provide a description that is worded well enough to be understood

Not able to read special characters such as @

Provide verbose output that clearly demonstrates the problem

• Run your yt-dlp command with -vU flag added (yt-dlp -vU <your command line>)
• Copy the WHOLE output (starting with [debug] Command-line config) and insert it below

Complete Verbose Output

[debug] Command-line config: ['-vU', 'https://stripchat.com/Rakhijaan@xh']
[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8, error utf-8, screen utf-8
[debug] yt-dlp version 2022.07.18 [135f05e]
[debug] Python 3.10.5 (CPython 64bit) - Linux-5.18.14-arch1-1-x86_64-with-glibc2.35 (glibc 2.35)
[debug] Checking exe version: ffmpeg -bsfs
[debug] Checking exe version: ffprobe -bsfs
[debug] exe versions: ffmpeg 5.0.1 (setts), ffprobe 5.0.1, rtmpdump 2.4
[debug] Optional libraries: Cryptodome-3.14.1, brotli-1.0.9, certifi-2021.10.08, mutagen-1.45.1, sqlite3-2.6.0, websockets-10.3
[debug] Proxy map: {}
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
Latest version: 2022.07.18, Current version: 2022.07.18
yt-dlp is up to date (2022.07.18)
[debug] [Stripchat] Extracting URL: https://stripchat.com/Rakhijaan@xh
[Stripchat] Rakhijaan: Downloading webpage
ERROR: [Stripchat] Rakhijaan: Model is offline
  File "/usr/lib/python3.10/site-packages/yt_dlp/extractor/common.py", line 644, in extract
    ie_result = self._real_extract(url)
  File "/usr/lib/python3.10/site-packages/yt_dlp/extractor/stripchat.py", line 44, in _real_extract
    raise ExtractorError('Model is offline', expected=True)