forwardport from enterprise: do not crash when no part is active during toolbar editing
forwardport from enterprise: do not crash when no part is active during toolbar editing

svn path=/trunk/KDE/kdepim/kontact/src/; revision=675091

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