Correct watcher reraising of exception

When an exception was caught and rethrown, it should call 'raise'
without any arguments because it shows the place where
an exception occured initially instead of place where
the exception re-raised

Change-Id: I662583cd3cda2424d5a510cae7e815c97a51c2fe

watcher/common/exception.py

@@ -86,7 +86,7 @@ class WatcherException(Exception):
         if not message:
             try:
                 message = self.msg_fmt % kwargs
-            except Exception as e:
+            except Exception:
                 # kwargs doesn't match a variable in msg_fmt
                 # log the issue and the kwargs
                 LOG.exception(_LE('Exception in string format operation'))
@@ -95,7 +95,7 @@ class WatcherException(Exception):
                               {'name': name, 'value': value})
 
                 if CONF.fatal_exception_format_errors:
-                    raise e
+                    raise
                 else:
                     # at least get the core msg_fmt out if something happened
                     message = self.msg_fmt