Remove canberra-gtk-module and pk-gtk-module Messages

Remove `canberra-gtk-module` and `pk-gtk-module` Messages

On some Linux^® distributions, one or both of these messages appear in the terminal window when starting MATLAB^®. These messages are informational and have no effect on MATLAB.

Gtk-Message: <timestamp>: Failed to load module "canberra-gtk-module"
Gtk-Message: <timestamp>: Failed to load module "pk-gtk-module"

To suppress these messages, open a terminal with root privileges and execute the relevant commands to install the libcanberra Linux package.

Red Hat Distributions

On Red Hat distributions (including CentOS and Fedora^®):

Install the package.
```
yum install libcanberra-gtk2
```

Set the GTK_PATH.

sh or bash commands:
```
$ export GTK_PATH=/usr/lib64/gtk-2.0
```
csh/tcsh commands:
```
% setenv GTK_PATH /usr/lib64/gtk-2.0
```

Debian-Based Distributions

On Debian^®-based distributions (including Ubuntu^®):

Install the package.
```
apt-get install libcanberra-gtk-module
```

Set the GTK_PATH.

sh or bash commands:

$ export GTK_PATH=/usr/lib/x86_64-linux-gnu/gtk-2.0

csh/tcsh commands:

% setenv GTK_PATH /usr/lib/x86_64-linux-gnu/gtk-2.0