Do not log ERROR when show isn't in list. Log WARNING instead.

Prevents the error log in webinterface from filling up, if there are downloads in your watch folder, which aren't in SB list

sickbeard/postProcessor.py

@@ -793,7 +793,7 @@ class PostProcessor(object):
         (show, season, episodes, quality, version) = self._find_info()
         if not show:
             self._log(u"This show isn't in your list, you need to add it to SB before post-processing an episode",
-                      logger.ERROR)
+                      logger.WARNING)
             raise exceptions.PostProcessingFailed()
         elif season == None or not episodes:
             self._log(u"Not enough information to determine what episode this is", logger.DEBUG)