lxc_container: remove BabyJSON

Removed the usage of baby json. This is in response to the fact
that the baby json functionality was removed in Ansible 1.8

Ref: https://github.com/ansible/ansible-modules-extras/issues/430

cloud/lxc/lxc_container.py

@@ -383,9 +383,7 @@ EXAMPLES = """
 try:
     import lxc
 except ImportError:
-    msg = 'The lxc module is not importable. Check the requirements.'
-    print("failed=True msg='%s'" % msg)
-    raise SystemExit(msg)
+    HAS_LXC = False
 
 
 # LXC_COMPRESSION_MAP is a map of available compression types when creating
@@ -1706,6 +1704,11 @@ def main():
         supports_check_mode=False,
     )
 
+    if not HAS_LXC:
+        module.fail_json(
+            msg='The `lxc` module is not importable. Check the requirements.'
+        )
+
     lv_name = module.params.get('lv_name')
     if not lv_name:
         module.params['lv_name'] = module.params.get('name')