fix bad logic resulting in failure to honor 'output' config.

This busted logic causes 'output' to not be paid any attention
to, and thus output is not written to /var/log/cloud-init-output.log.

cloudinit/util.py

@@ -1146,7 +1146,7 @@ def chownbyname(fname, user=None, group=None):
 # this returns the specific 'mode' entry, cleanly formatted, with value
 def get_output_cfg(cfg, mode):
     ret = [None, None]
-    if cfg or 'output' not in cfg:
+    if not cfg or 'output' not in cfg:
         return ret
 
     outcfg = cfg['output']