(use (prefix uri-generic generic:)
     (prefix uri-common common:))

(define url 
  "https://img.discogs.com/dMvk8q681FkVCkhv3qRvTfwlLZk=/fit-in/300x300/filters:strip_icc():format(jpeg):mode_rgb():quality(40)/discogs-images/R-8062430-1454420247-1268.jpeg.jpg")

(define req-uri 
  (common:uri-reference url))

(let ((u (common:uri->uri-generic req-uri)))
  (print
    (common:uri->string
      (common:uri-generic->uri
	(generic:update-uri
	  u
	  path: (generic:uri-path u))))))


;; result:
;; https://img.discogs.com/dMvk8q681FkVCkhv3qRvTfwlLZk=/fit-in/300x300/filters:strip_icc():format(jpeg):mode_rgb():quality(40)/discogs-images/R-8062430-1454420247-1268.jpeg.jpg