Initialize tempEpisodeNumber

Caused an error:
File
"C:\Users\xnappo\AppData\Roaming\XBMC\addons\plugin.video.xbmb3c\service.py",
line 983, in updateRandom
self.logMsg("RandomEpisodeMB3." + str(item_count) + ".EpisodeNo = " +
tempEpisodeNumber, debugLogging)
UnboundLocalError: local variable 'tempEpisodeNumber' referenced before
assignment