fix: correct broken link from Frama-C's RSS feed (ocaml#2648)

data/planet/frama-c/the-guide-to-software-verification-with-frama-c-is-available.md

@@ -1,7 +1,7 @@
 ---
 title: The Guide to Software Verification with Frama-C is available
 description:
-url: https://frama-c.comhttps//link.springer.com/book/10.1007/978-3-031-55608-1
+url: https//link.springer.com/book/10.1007/978-3-031-55608-1
 date: 2024-08-08T00:00:00-00:00
 preview_image:
 authors: