Fix building with glib 2.68:

https://github.com/qtwebkit/qtwebkit/issues/1057

Patch copied from upstream pull request:

https://github.com/qtwebkit/qtwebkit/pull/1058/commits/5b698ba3faffd4e198a45be9fe74f53307395e4b

diff -aurN qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h qtwebkit-5.212.0-alpha4-mod/Source/WTF/wtf/glib/GRefPtr.h
--- qtwebkit-5.212.0-alpha4/Source/WTF/wtf/glib/GRefPtr.h	2020-03-04 18:16:37.000000000 +0100
+++ qtwebkit-5.212.0-alpha4-mod/Source/WTF/wtf/glib/GRefPtr.h	2021-04-05 06:58:44.763328636 +0200
@@ -29,9 +29,6 @@
 #include <wtf/RefPtr.h>
 #include <algorithm>
 
-extern "C" void g_object_unref(gpointer);
-extern "C" gpointer g_object_ref_sink(gpointer);
-
 namespace WTF {
 
 enum GRefPtrAdoptType { GRefPtrAdopt };
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<tr class='logheader'><td><span title='2019-10-23 16:40:17 +0200'>2019-10-23</span></td><td class='logsubject'><a href='/guix/commit/tests/cve-sample.json?id=74afaa37d5dec1a9d1b83951529ba69d8947fb07'>cve: Rewrite to read the JSON feed instead of the XML feed.</a></td><td>Ludovic Courtès</td></tr>
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The XML feed was discontinued on Oct. 16th, 2019:

  &lt;https://nvd.nist.gov/General/News/XML-Vulnerability-Feed-Retirement-Phase-3&gt;

* guix/cve.scm (string-&gt;date*): New procedure.
(&lt;cve-item&gt;, &lt;cve&gt;, &lt;cve-reference&gt;): New record types.
(cpe-match-&gt;cve-configuration, configuration-data-&gt;cve-configurations)
(json-&gt;cve-items, version-matches?): New procedures.
(yearly-feed-uri): Change URL to refer to JSON feed.
(cpe-&gt;product-alist, %parse-vulnerability-feed)
(xml-&gt;vulnerabilities): Remove.
(cve-configuration-&gt;package-list, merge-package-lists)
(cve-item-&gt;vulnerability, json-&gt;vulnerabilities): New procedures.
(write-cache): Use 'json-&gt;vulnerabilities' instead of
'xml-&gt;vulnerabilities', and remove 'parameterize'.
(vulnerabilities-&gt;lookup-proc): Use 'version-matches?' when VERSION is
true.
* tests/cve.scm (%sample): Use 'tests/cve-sample.json'.
(%expected-vulnerabilities): Rewrite accordingly.
("json-&gt;cve-items", "cve-item-published-date")
("json-&gt;vulnerabilities"): New tests.
("xml-&gt;vulnerabilities"): Remove.
("vulnerabilities-&gt;lookup-proc"): Adjust to new vulnerabilities.
* tests/cve-sample.json: New file.
* tests/cve-sample.xml: Remove.
* Makefile.am (EXTRA_DIST): Adjust accordingly.
* doc/guix.texi (Invoking guix lint): Update nist.gov URLs.


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