Update SQL schema, allow NULL
Update SQL schema, allow NULL

codeformunich/Muenchen-Transparent,CatoTH/Muenchen-Transparent,codeformunich/Muenchen-Transparent,CatoTH/Ratsinformant,CatoTH/Ratsinformant,CatoTH/Ratsinformant,CatoTH/Ratsinformant,CatoTH/Muenchen-Transparent