Fixes for all iOS versions that are current - including iOS 12

[johnwyles]

I have tested this and it works:

python --version
# => Python 3.7.1

python sms-backup.py -o ~/Desktop/output.csv -d "%m-%d-%Y %H:%M:%S" -f csv -m "John Wyles" -a "555-555-5555=John Doe" -p "+15555555555" -i ~/Desktop/backup_dir/HomeDomain/Library/SMS/sms.db

head -n 2 ~/Desktop/output.csv
# "Date","From","To","Text"
# "11-01-2018 06:39:42","John Wyles","John Wyles","Hello World!"

[johnwyles]

deja vu. i'm looking into performing this again years and years later and lo-and-behold the last PR on it was... me. Guess I will give it a crack again! Wish him and me luck!