Update fakku.py

Hello again, a few improvements suggestions: 
107 - 111 if folder is empty The Download Fail completely. if we were to retry later on will fail as folder exist on line 88. therefore lets delete the folder 
208 - 210 suggest to call the help so inexperienced users can check the app usage when provide no args also check when ever args.url are none as this is possible is no args are parsed or provided... 
if this is not a good option also can consider outputing: "No URL\n use -h parameter for help"