Cron based mass importer fixed

After the changes that have been made the current ways of
importing data into sendy is as follows -

1. Upload files not larger than 1MB throug the 'Add Subscribers'
interface that is provided at - http://messenger.aamaadmiparty.org/
2. For larger files > first check that the number of columns in the file
and thier order matches the fields settings > Then move the file somewhere
on the server where sendy is hosted > Split the file into many files with
data in the range of 5000 to 10000 rows > Name the files in the format
[userid]-[listid][anything]. (eg: 1-2-aa, 1-2-ab, 1-2.csv etc.)

userid = Numeric id associated with your login (you can use 1)
listid = Numeric id of the list you are importing the data in

references AamAadmiParty/mass-emailer-sendy#3