Minor optimization not send "emit changed()" if we don't add new string
Minor optimization
not send "emit changed()" if we don't add new string

svn path=/branches/kdepim/enterprise/kdepim/; revision=960937

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