Fix compatibility with Qt 5.15.

Patch copied from upstream source repository:

https://bazaar.launchpad.net/~adamreichold/qpdfview/trunk/revision/2104

--- a/sources/model.h	2017-04-19 21:01:25 +0000
+++ b/sources/model.h	2020-06-09 06:24:11 +0000
@@ -24,6 +24,7 @@
 #define DOCUMENTMODEL_H
 
 #include <QList>
+#include <QPainterPath>
 #include <QtPlugin>
 #include <QWidget>
 #include <QVector>

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<tr><td><span title='2021-12-22 10:53:19 +0100'>2021-12-22</span></td><td><a href='/guix/commit/tests/keys/ed25519-3.sec?id=9ebc9ca070a21ba0aeb3f61202a8071bb250ccc8'>tests: Move keys into ./tests/keys/ and add a third ed25519 key.</a><span class='msg-avail'>...<span class='msg-tooltip'>The third key will be used in an upcoming commit.

Rename public keys to .pub.

* guix/tests/gnupg.scm (%ed25519-3-public-key-file): New variable.
(%ed25519-3-secret-key-file): New variable.
(%ed25519-2-public-key-file): Renamed from %ed25519bis-public-key-file.
(%ed25519-2-secret-key-file): Renamed from %ed25519bis-secret-key-file.
* tests/keys/ed25519-3.key: New file.
* tests/keys/ed25519-3.sec: New file.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Attila Lendvai</td></tr>