gnu: psutils: Use 'modify-phases'.

* gnu/packages/ghostscript.scm (psutils)[arguments]: Use 'modify-phases'
syntax.

gnu/packages/ghostscript.scm

@@ -100,8 +100,8 @@ paper size.")
    (arguments
     `(#:tests? #f ; none provided
       #:phases
-      (alist-replace
-       'configure
+      (modify-phases %standard-phases
+        (replace 'configure
           (lambda* (#:key inputs outputs #:allow-other-keys #:rest args)
            (let ((perl (assoc-ref inputs "perl"))
                  (out (assoc-ref outputs "out")))
@@ -115,8 +115,8 @@ paper size.")
               (("-mkdir") "mkdir -p"))
             ;; drop installation of non-free files
             (substitute* "Makefile"
-           ((" install.include") ""))))
-      %standard-phases)))
+              ((" install.include") "")))
+           #t)))))
    (synopsis "Collection of utilities for manipulating PostScript documents")
    (description
     "PSUtils is a collection of utilities for manipulating PostScript