Tools: fix archlinux install script

need setuptools on venv

Tools/environment_install/install-prereqs-arch.sh

@@ -26,7 +26,7 @@ BASE_PKGS="base-devel ccache git gsfonts tk wget gcc"
 SITL_PKGS="python-pip python-setuptools python-wheel python-wxpython opencv python-numpy python-scipy"
 PX4_PKGS="lib32-glibc zip zlib ncurses"
 
-PYTHON_PKGS="future lxml pymavlink MAVProxy pexpect argparse matplotlib pyparsing geocoder pyserial empy==3.3.4 dronecan"
+PYTHON_PKGS="future lxml pymavlink MAVProxy pexpect argparse matplotlib pyparsing geocoder pyserial empy==3.3.4 dronecan setuptools wheel"
 
 # GNU Tools for ARM Embedded Processors
 # (see https://launchpad.net/gcc-arm-embedded/)