Bug 27726: Increase 'content' field size

Bug 27726: Increase 'content' field size

This alternate patch increases the field size from a 255 character
varchar to a 65535 character text field. This allows for more detailed
problem reports to be submitted.

Signed-off-by: Amit Gupta <amitddng135@gmail.com>
Signed-off-by: Petro Vashchuk <stalkernoid@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 7c854a87d221a92051411d822121398f2440ae1e)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>