Do not setup cockpit on Ubuntu 16.04.

1.Base/4.cockpit/0_setup.py

@@ -4,6 +4,12 @@ import os
 
 
 def setup(interactive=False):
+    if os.path.exists('/etc/lsb-release'):
+        with open('/etc/lsb-release', 'r') as fo:
+            content = fo.read()
+        if '16.04' in content:
+            utils.log('Skipping cockpit setup because OS is Ubuntu 16.04.')
+            return
     cmds = [
         'apt install -y software-properties-common',
         'add-apt-repository universe',