another crash guard for passing invalid dates to setHolidayMasks() MERGE: e4,trunk,4.3
another crash guard for passing invalid dates to setHolidayMasks()
MERGE: e4,trunk,4.3

svn path=/branches/kdepim/enterprise/kdepim/; revision=1030061

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi