boost 1.70+compilation breaks as the get_io_service function has been removed.

[jamescowens]

Reported by @scribblemaniac in #1493.

[g1itch]

Maybe this will help: gnuradio/gnuradio#2451

[iFoggz]

yea the define way would work but the developers agreed that it wasn't the best way but i do agree with the way they did this fix with the merge they ended up using gnuradio/gnuradio@6dc8229

[iFoggz]

ill have a look at this one. i have boost 1.64 and boost 1.70 installed as well.

[iFoggz]

#1533 fixes this incompatibility.