ubuntu.sh: source .profile before checking for ARM GCC
ubuntu.sh: source .profile before checking for ARM GCC

to avoid downloading and installing ARM GCC again if the script is
reran immediately after e.g. because it failed the first time.

PX4/Firmware,PX4/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,PX4/Firmware,krbeverx/Firmware,krbeverx/Firmware,krbeverx/Firmware,krbeverx/Firmware,PX4/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware