cloud-init-cfg: log warning with traceback on failure of a config module

Previously, all you would get was a warning to the console on config
module failure.  This changes to get a stack trace of the failure to the
console, which is much easier for debugging.

cloud-init-cfg.py

@@ -22,6 +22,7 @@ import cloudinit
 import cloudinit.CloudConfig
 import logging
 import os
+import traceback
 
 def Usage(out = sys.stdout):
     out.write("Usage: %s name\n" % sys.argv[0])
@@ -95,6 +96,7 @@ def main():
                 (name, freq, run_args ))
             cc.handle(name, run_args, freq=freq)
         except:
+            log.warn(traceback.format_exc())
             err("config handling of %s, %s, %s failed\n" %
                 (name,freq,run_args), log)
             failures.append(name)

cloudinit/CloudConfig/__init__.py

@@ -56,6 +56,5 @@ class CloudConfig():
             self.cloud.sem_and_run("config-" + name, freq, handler,
                 [ name, self.cfg, self.cloud, cloudinit.log, args ])
         except:
-            cloudinit.log.debug(traceback.format_exc())
             raise