make border golden

The black border was not visible on black task bars.
It looked like the white background with the R was the logo, which made the
impression that the logo was not scaled correctly.

main.py

@@ -23,7 +23,7 @@ MAX_LINE_LENGTH = 4096
 logging.basicConfig(level=logging.INFO)
 log = logging.getLogger("main")
 
-raven_icon = "icon7.png"
+raven_icon = "icon7_gold3.png"
 
 
 class MainWindow(QMainWindow):
@@ -190,12 +190,13 @@ def stop_signal(signum, _stackframe):
 
 if __name__ == "__main__":
     app = QApplication(sys.argv)
-    app.setWindowIcon(QIcon(raven_icon)) # works only for Linux
+    app.setWindowIcon(QIcon(raven_icon))  # works only for Linux
 
     # make icon appear in Windows
     # see https://stackoverflow.com/questions/1551605/how-to-set-applications-taskbar-icon-in-windows-7/1552105#1552105
-    myappid = 'opentext.ravenlog.0.1'  # arbitrary string
-    ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(myappid)
+    if sys.platform == 'win32' or sys.platform == 'cygwin':
+        myappid = 'opentext.ravenlog'  # arbitrary string
+        ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(myappid)
 
     # translator = QTranslator()
     # if translator.load(QLocale("de"), "messages_de.ts"):