gnu: source-highlight: Update to 3.1.8.

* gnu/packages/pretty-print.scm (source-highlight): Update to 3.1.8.

gnu/packages/pretty-print.scm

@@ -144,7 +144,7 @@ (define-public enscript
 (define-public source-highlight
   (package
     (name "source-highlight")
-    (version "3.1.7")
+    (version "3.1.8")
     (source
      (origin
       (method url-fetch)
@@ -152,7 +152,7 @@ (define-public source-highlight
                           version ".tar.gz"))
       (sha256
        (base32
-        "1s49ld8cnpzhhwq0r7s0sfm3cg3nhhm0wla27lwraifrrl3y1cp1"))
+        "18xdalxg7yzrxc1njzgw7aryq2jdm7zq2yqz41sc7k6il5z6lcq1"))
       (patches
        (list (search-patch
               ;; Patch submitted as Savannah item #41786