devel/thrift-cpp: fix build on big-endian, unbreak on i386

1. Code for BE has issues:
In file included from /wrkdirs/usr/ports/devel/thrift-cpp/work/thrift-0.22.0/lib/cpp/src/thrift/TApplicationException.cpp:21:
/wrkdirs/usr/ports/devel/thrift-cpp/work/thrift-0.22.0/lib/cpp/src/thrift/protocol/TProtocol.h:669:66: error: expected ')'
  669 |   static uint16_t toWire16(uint16_t x)   {return THRIFT_htoles(x);}
      |                                                                  ^
/wrkdirs/usr/ports/devel/thrift-cpp/work/thrift-0.22.0/lib/cpp/src/thrift/protocol/TProtocol.h:669:50: note: to match this '('
  669 |   static uint16_t toWire16(uint16_t x)   {return THRIFT_htoles(x);}
      |                                                  ^
/wrkdirs/usr/ports/devel/thrift-cpp/work/thrift-0.22.0/lib/cpp/src/thrift/protocol/TProtocol.h:179:28: note: expanded from macro 'THRIFT_htoles'
  179 | #  define THRIFT_htoles(n) bswap_16(n)
      |                            ^
/wrkdirs/usr/ports/devel/thrift-cpp/work/thrift-0.22.0/lib/cpp/src/thrift/protocol/TProtocol.h:173:9: note: expanded from macro 'bswap_16'
  173 |       ( (((n) & (static_cast<unsigned short>(0xff00ul)) >> 8)  \
      |         ^
2. Builds fine on i386.
3. While here, remove MAKE_JOBS_UNSAFE=yes. I assume that if it builds on a POWER9 box with 176 threads, that's enough.