You uploaded your image.ini.append.php file from your local computer to the server. This file has the info about path and filename of the ImageMagick "convert" (or "convertim") file.
Of course, this file/directory is not the same on the server.
You must change this .ini setting on the server to reflect the directoryname and filename of "convert" of the ImageMagick installation on the server.
Of course, this required, that you have ImageMagick installed and running on your server AND will only work, when PHP safe mode in DISabled. The image.ini.append.php file should be in settings/override