gnu: fribidi: Remove defunct replacement.

* gnu/packages/fribidi.scm (fribidi)[replacement]: Remove.
(fribidi/fixed): Remove variable.

gnu/packages/fribidi.scm

@@ -27,7 +27,6 @@
 
 (define-public fribidi
   (package
-    (replacement fribidi/fixed)
     (name "fribidi")
     (version "1.0.7")
     (source
@@ -48,10 +47,3 @@ Algorithm.  This algorithm is used to properly display text in left-to-right
 or right-to-left ordering as necessary.")
     (home-page "https://github.com/fribidi/fribidi")
     (license lgpl2.1+)))
-
-(define fribidi/fixed
-  (package
-    (inherit fribidi)
-    (source
-      (origin (inherit (package-source fribidi))
-              (patches (search-patches "fribidi-CVE-2019-18397.patch"))))))