What have you installed before?
Apt-get install...?
sudo apt-get install build-essential
sudo apt-get install libssl-dev
sudo apt-get install libdb++-dev
sudo apt-get install libboost-all-dev
sudo apt-get install libqrencode-dev
sudo apt-get install libgmp3-dev
sudo apt-get install libzmq3-dev
sudo apt-get install libgmp3-dev
Yes, I installed all of them
Don't forget to
sudo apt-get update
before installing the packages. You may have an old version of one of them.
Then try
make -f makefile.unix clean
make -f makefile.unix USE_UPNP=1
Pretty sure I've seen this particular build error before, i can't quite remember what fixed it.