Switch menu icon for English man page PDF to match the other english PDF entries.

Author: petterreinholdtsen

debian/extras/usr/share/applications/linuxcnc-manualpages.desktop

@@ -4,7 +4,7 @@ Name=LinuxCNC Manual Pages
 Comment=Integrator Information
 Type=Application
 Exec=xdg-open /usr/share/doc/linuxcnc/LinuxCNC_Manual_Pages.pdf
-Icon=linuxcncicon
+Icon=linuxcnc_en
 X-GNOME-DocPath=
 Terminal=false
 StartupNotify=false