disable creation of imapsync logs

disable the writing of logs in current workdir to prevent permission errors
I'd expect this to break since it's a list that's passed to ```Popen```. From https://docs.python.org/2/library/subprocess.html#subprocess.Popen:
> args should be a sequence of program arguments or else a single string. By default, the program to execute is the first item in args if args is a sequence. If args is a string, the interpretation is platform-dependent and described below. See the shell and executable arguments for additional differences from the default behavior. Unless otherwise stated, it is recommended to pass args as a sequence.

That means you should pass them as seperate arguments: ```['imapsync', '--nolog', '--noreleasecheck']```.