fix of osmoload, flashing c155 works

[Sylvain Munaut]

> just fixed the issue from 29c3, where flashing of phones did not work
> anymore. if no one complains, i will apply it.

1) Can you make those patch over my testing branch instead ? The build
system was completely reworked and the merge is going to suck if you
change the makefile in master

2) Your patch enables TX and flash write by default, that's bad.

Cheers,

   Sylvain