vagrant: Set `$PROJECT_HOME` - `$BASE` was set to the default path

Yarko's `$BASE` patch has been merged and rewritten since
the original pull request was created, resulting in the `$BASE` being
incorrectly set to the default `/home/vagrant/edx_all` by the new code.

scripts/vagrant-provisioning.sh

@@ -65,7 +65,7 @@ chown vagrant.vagrant /opt/edx
 [[ -f ~vagrant/.bash_profile ]] && {
     mv ~vagrant/.bash_profile ~vagrant/.bash_profile.bak
 }
-sudo -u vagrant -i bash -c "cd /opt/edx/edx-platform && ./scripts/create-dev-env.sh -ynq"
+sudo -u vagrant -i bash -c "cd /opt/edx/edx-platform && PROJECT_HOME=/opt/edx ./scripts/create-dev-env.sh -ynq"
 
 
 # Virtualenv - Always load ####################################################