use own icons since using stock icons might create issues in KDE

data/applications/pamac-install.desktop

@@ -125,7 +125,7 @@ Categories=System;
 Exec=pamac-install %F
 Terminal=false
 Type=Application
-Icon=system-software-install
+Icon=/usr/share/pamac/icons/32x32/apps/pamac.png
 StartupNotify=true
 NoDisplay=true
 MimeType=application/x-xz-compressed-tar;