Use bash to run the initial script to create mesh username

src/freedombone-image-customise

     echo 'Name=Set Username' >> $START_DESKTOP3
     echo 'Type=Application' >> $START_DESKTOP3
     echo 'Comment=Set username' >> $START_DESKTOP3
-    echo "Exec=mate-terminal -e /home/${MY_USERNAME}/mesh-desktop.sh" >> $START_DESKTOP3
+    echo "Exec=mate-terminal -e bash -c \"/home/${MY_USERNAME}/mesh-desktop.sh\"" >> $START_DESKTOP3
     echo 'Icon=user-away' >> $START_DESKTOP3
     echo 'Terminal=false' >> $START_DESKTOP3
     echo 'Categories=Application;' >> $START_DESKTOP3