OC ReMix URLs are cleaned up having the slug removed, but a trailing slash is left. Cleanup should follow the example of the main remix URLs and not leave a trailing slash.

• https://ocremix.org/remix/OCR04187 gets cleaned up as https://ocremix.org/remix/OCR04187/.
• https://ocremix.org/song/451/kraids-chamber gets cleaned up as https://ocremix.org/song/451/ when it should be https://ocremix.org/song/451.
• https://ocremix.org/artist/17929/gaspode gets cleaned up as https://ocremix.org/artist/17929/ when it should be https://ocremix.org/artist/17929.