Checks for downloaded installer.

checkdownload.m

 if ( self->_packageFilePath )
  {
    v7 = objc_msgSend(&OBJC_CLASS___NSFileManager, "defaultManager");
    v8 = (void *)objc_retainAutoreleasedReturnValue(v7);
    v3 = (unsigned int)objc_msgSend(v8, "fileExistsAtPath:", self->_packageFilePath);
    objc_release(v8);
    if ( (_BYTE)v3 )
    {
      v9 = -[ZMLauncherMgr installPkg:](self, "installPkg:", self->_packageFilePath);
      goto LABEL_21;
    }
    -[ZMLauncherMgr setPackageFilePath:](self, "setPackageFilePath:", 0LL);
  }