fix: [python-venv] python source url in ``tar.bz2`` could not be found anymore.

Since 2.7.6, tar.bz2 are not anymore provided for python on the ftp web
site. To fix this, we now use ``.tgz`` which seems to have been used
across all versions.

precise/python-venv/hooks/install

@@ -11,8 +11,8 @@ VERSION="2.7.5"
 apt-get install wget bzip2 build-essential -y --force-yes
 apt-get install libreadline-dev libbz2-dev libz-dev libssl-dev libsqlite3-dev libgdbm-dev libldap2-dev  -y --force-yes
 cd /tmp
-wget http://www.python.org/ftp/python/$VERSION/Python-$VERSION.tar.bz2
-tar xjf Python-$VERSION.tar.bz2
+wget http://www.python.org/ftp/python/$VERSION/Python-$VERSION.tgz
+tar xzf Python-$VERSION.tgz
 cd Python-$VERSION
 ./configure --prefix=/opt/apps/python-$VERSION
 make