Use official OMERO.matlab name when loading toolbox with loadOmero()

Noticed while answering https://www.openmicroscopy.org/community/viewtopic.php?f=6&t=7469. This is a trivial change which unifies the displayed name of the toolbox with the documentation/downloads.

To test the PR, download the merge OMERO.matlab toolbox, load it with

```
>> loadOmero()
```
and check the displayed name is correct.