Numeric values with leading zeroes were incorrectly copied into a
SQLDA (SQL Descriptor Area), leading to wrong results in ECPG programs.

Report and patch by Daisuke Higuchi.  Back-patch to all supported
versions.

Discussion: https://postgr.es/m/1803D792815FC24D871C00D17AE95905C71161@g01jpexmbkw24