Bug 30185: Missing return in db rev 210600003.pl

Bug 30185: Missing return in db rev 210600003.pl

db rev files are constructed with a return {...}, db rev 210600003.pl is missing return word.
I don't know if it can impact the db upgrade but we should fix it for consistency.

To test upgrade from a version 21.05 and check db rev is applied.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>