add FRITZ.Box_6840_LTE_BETA.105.05.29-24421 (refs #1910)

git-svn-id: file:///var/svn/freetz/trunk@9961 149334a1-2f27-0410-a3b9-fc62619ac1e6
Firmware bump: 7240 73.05.50 rev24454 (refs #1910)

git-svn-id: file:///var/svn/freetz/trunk@9962 149334a1-2f27-0410-a3b9-fc62619ac1e6