Bug 23826: Correction for missing "F" -> "OVERDUE" change

Bug 23826: Correction for missing "F" -> "OVERDUE" change

When replacing F and FU with 'OVERDUE' + status in bug 22521 I missed
the cases inside the maninvoice template. This patch should correct
that mistake.

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 9d33b82fe8ada8aee4e62bed5e147fe15f72e2e0)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>