Define macro for boost >= 1.66

[trourance]

This is to fix the issue with raspbian buster #44

[cygnusxi]

@trourance can you test the current version on raspbian to see if this pull is still required? Thanks!

[trourance]

It seems that the master branch doesn't compile anymore on raspbian.
I get the following error:

In file included from main.h:8,
                 from db.h:8,
                 from checkpoints.cpp:10:
bignum.h:104:5: error: ‘CBigNum::CBigNum(long long int)’ cannot be overloaded with ‘CBigNum::CBigNum(int64_t)’
     CBigNum(long long int n)      { init(); setuint64(n); }
     ^~~~~~~
bignum.h:98:5: note: previous declaration ‘CBigNum::CBigNum(int64_t)’
     CBigNum(int64_t n)            { init(); setint64(n); }
     ^~~~~~~
make: *** [makefile.raspberrypi:149: obj/checkpoints.o] Error 1

[Nuitari]

What versions of gcc and openssl do you have?

[trourance]

I've tried with both version of libssl, same result.
gcc version 8.3.0 (Raspbian 8.3.0-6+rpi1)
libssl1.0-dev:armhf 1.0.2q-2 or libssl-dev:armhf 1.1.1d-0+deb10u3+rpt1

[pwnzjoon00b]

Nice, I was able to successfully build curecoind on my rPi making this change!