Bug 18536: Generating CSV using profile in serials late issues doesn't work as described

Bug 18536: Generating CSV using profile in serials late issues doesn't work as described

Description on editing csv profiles says:

"You can also use your own headers (instead of the ones from Koha) by
prefixing the field name with an header, followed by the equal sign."

So the header should be optional, but in fact it's mandatory. Also the
regular expression to cut table name from beginning of db column is not
right.

Test plan:

0. Don't apply the patch
1. Make two CSV profiles for exporting late issues
    a) SUPPLIER=aqbooksellers.name|TITLE=subscription.title|ISSUENUMBER=serial.serialseq|LATE SINCE=serial.planneddate
    b) aqbooksellers.name|TITLE=subscription.title|ISSUE NUMBER=serial.serialseq|LATE SINCE=serial.planneddate
2. Export late issues, profile a) works as expected, profile b) doesn't
3. Apply the patch
4. Both profiles should work

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 6b8f9d7e14a8b93143185e814464393ef275631d)
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>