Remove icon credits from about box

* Moved credits to CREDITS file
* Updated exchange icon with higher hue contrast for better visibility on dark backgrounds

CREDITS

@@ -1,6 +1,8 @@
 To know who contributed to dupeGuru, you can look at the commit log, but not all contributions
 result in a commit. This file lists contributors who don't necessarily appear in the commit log.
 
+* Jason Cho, Exchange icon
+* schollidesign (https://findicons.com/pack/1035/human_o2), Zoom-in, Zoom-out, Zoom-best-fit, Zoom-original icons
 * Jérôme Cantin, Main icon
 * Gregor Tätzner, German localization
 * Frank Weber, German localization

qtlib/about_box.py

@@ -69,21 +69,6 @@ class AboutBox(QDialog):
         self.verticalLayout.addWidget(self.label_3)
         self.label_3.setText(tr("Licensed under GPLv3"))
         self.label = QLabel(self)
-        self.label_4 = QLabel(self)
-        self.label_4.setWordWrap(True)
-        self.label_4.setTextFormat(Qt.RichText)
-        self.label_4.setOpenExternalLinks(True)
-        self.label_4.setText(tr(
-            """<img src=":/exchange" alt="Exchange" width="16" height="16"> icon
- made by <a href="http://jasoncho.ca/"> Jason Cho</a> (used with permission).
-<br>
-<img src=":/zoom_in" alt="Zoom In" width="16" height="16">
-<img src=":/zoom_out" alt="Zoom Out" width="16" height="16">
-<img src=":/zoom_best_fit" alt="Zoomt Best Fit" width="16" height="16">
-<img src=":/zoom_original" alt="Zoom Original" width="16" height="16">
- icons made by <a href="https://findicons.com/pack/1035/human_o2">schollidesign</a>
- (licensed under GPL)."""))
-        self.verticalLayout.addWidget(self.label_4)
         font = QFont()
         font.setWeight(75)
         font.setBold(True)