If calibre server has only 1 library, program crashes.
Causes
I check for tags option to find all libraries but when only exists 1 library this tags not exists, so an error is generated.
Possible Solution:
Catch this error and proced because it's not inpeditive, since when it's only 1 library, calibre accepts an random name and it will use the only library that exists
In calibre_shodan.py file make a method to iterate over all found hosts and use method check_open available on calibre_tools.py to check if calibre server is unauthenticated