accountlines.accounttype is currently a short varchar(5) field for to
store accounttype codes. Koha is moving towards more descriptive codes
which require a larger capacity varchar(16).
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com> Signed-off-by: Josef Moravec <josef.moravec@gmail.com> Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com> Signed-off-by: Nick Clemens <nick@bywatersolutions.com>