This commit reverts the change coming from
675fd0af.

On a test machine, running the basic simulator (both eNB, UE
and T tracer) with 100 RBs eats too much of memory on a computer
with 8GB of RAM, leading to a reboot because the computer
was not responsive anymore.

Other solutions are needed to solve the memory issues, but
multiplying by 50 this number is not a good one, at least
not in the basic mode of operation. If this value needs
to be that big, a #ifdef #else #endif may be used.