Updated and fixed the debian/ubuntu build doc

Changes:
- Brought back the  `--with-boost-libdir=/usr/lib/x86_64-linux-gnu` parameter to give to the `bootstrap.sh` script, it prevents the `configure: error: Boost.System library not found. Try using --with-boost-system=lib` error
- Removed the `./configure --enable-logging --enable-debug --enable-dht` line, it's already done by the `bootstrap.sh` script
- Renamed the file (bilding->building)