extra_packages does not work with more than one package

[Benjamin Allot]

When setting the extra_packages configuration to "irssi screen" I hav the following log

| 2020-02-19 09:03:39 DEBUG config-changed E: Unable to locate package irssi screen

The reason is the way the command is computed. I added some logs to confirm it:

| 020-02-19 09:03:38 INFO juju-log Running ['apt-get', '-y', 'install', '-qq', 'irssi screen']

A quick fix that works (and we could expand to integrate comma as well) is to simply iterate over the string passed to the apt_get_install method.

diff --git a/hooks/hooks.py b/hooks/hooks.py
index b2647f7..bbfd91a 100755
--- a/hooks/hooks.py
+++ b/hooks/hooks.py
@@ -57,7 +57,8 @@ def apt_get_install(package=None):
     if package is None:
         return False
     cmd_line = ['apt-get', '-y', 'install', '-qq']
- cmd_line.append(package)
+ for pkg in package.split(' '):
+ cmd_line.append(pkg)
     return subprocess.call(cmd_line)