When an SQL query has comments then those were deleted
when switching to design view. This is fixed and the comments
are maintained. In the case the query is edited in design
view then the comments are inevitably lost.
Change-Id: Ibcf6e36fce88a526c7340d352aca9859b1b3714e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/205441
Tested-by: Jenkins
Reviewed-by: Vissarion Fisikopoulos <vfisikop@libreoffice.org>