gnu: gnucash: Convert price-quotes-perl patch to a phase.

* gnu/packages/patches/gnucash-price-quotes-perl.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Unregister it.
* gnu/packages/gnucash.scm (gnucash)[patches]: Remove it.
[phases]{fix-finance-quote-check}: Implement it using SUBSTITUTES*.

gnu/local.mk

@@ -831,7 +831,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/gmp-faulty-test.patch			\
   %D%/packages/patches/gnome-todo-libical-compat.patch		\
   %D%/packages/patches/gnome-tweak-tool-search-paths.patch	\
-  %D%/packages/patches/gnucash-price-quotes-perl.patch		\
   %D%/packages/patches/gnucash-disable-failing-tests.patch	\
   %D%/packages/patches/gnucash-fix-test-transaction-failure.patch \
   %D%/packages/patches/gnutls-skip-trust-store-test.patch	\

gnu/packages/gnucash.scm

@@ -60,8 +60,7 @@ (define-public gnucash
        (sha256
         (base32
          "0grr5qi5rn1xvr7qx5d7mcxa2mcgycy2b325ry73bb485a6yv5l3"))
-       (patches (search-patches "gnucash-price-quotes-perl.patch"
-                                "gnucash-disable-failing-tests.patch"
+       (patches (search-patches "gnucash-disable-failing-tests.patch"
                                 "gnucash-fix-test-transaction-failure.patch"))))
     (build-system cmake-build-system)
     (inputs
@@ -119,6 +118,13 @@ (define-public gnucash
                  (("set\\(SHELL /bin/bash\\)")
                   (string-append "set(SHELL " (which "bash") ")")))
                #t)))
+         ;; After wrapping gnc-fq-check and gnc-fq-helper we can no longer
+         ;; execute them with perl, so execute them directly instead.
+         (add-after 'unpack 'fix-finance-quote-check
+           (lambda _
+             (substitute* "libgnucash/scm/price-quotes.scm"
+               (("\"perl\" \"-w\" ") ""))
+             #t))
          ;; There are about 100 megabytes of documentation.
          (add-after 'install 'install-docs
            (lambda* (#:key inputs outputs #:allow-other-keys)

gnu/packages/patches/gnucash-price-quotes-perl.patch

@@ -1,24 +0,0 @@
-After wrapping gnc-fq-check and gnc-fq-helper we can no longer execute them
-with perl, so execute them directly instead.
-
-diff -ur gnucash-3.2.old/libgnucash/scm/price-quotes.scm gnucash-3.2/libgnucash/scm/price-quotes.scm
---- gnucash-3.2.old/libgnucash/scm/price-quotes.scm	2018-09-15 00:48:33.718389646 -0400
-+++ gnucash-3.2/libgnucash/scm/price-quotes.scm	2018-09-15 13:51:49.249862724 -0400
-@@ -74,7 +74,7 @@
-     (define (start-program)
-       (if (not (string-null? gnc:*finance-quote-check*))
-           (set! program (gnc-spawn-process-async
--                         (list "perl" "-w" gnc:*finance-quote-check*) #t))))
-+                         (list gnc:*finance-quote-check*) #t))))
- 
-     (define (get-sources)
-       (if (not (null? program))
-@@ -158,7 +158,7 @@
-     (define (start-quoter)
-       (if (not (string-null? gnc:*finance-quote-helper*))
-           (set! quoter (gnc-spawn-process-async
--                        (list "perl" "-w" gnc:*finance-quote-helper*) #t))))
-+                        (list gnc:*finance-quote-helper*) #t))))
- 
-     (define (get-quotes)
-       (if (not (null? quoter))