Negate unsupported warning caused by appimaged

[electricduck]

On login, the above notification appears, which is coming from appimaged as the OS is "not supported" (even though it is). This warning is superfluous and confusing to new users, so we need to stop it occuring.

This error is currently not disable-able. See:

• Need a way to disable all desktop notifications probonopd/go-appimage#178
• appimaged doesn't work probonopd/go-appimage#133

[electricduck]

Since this will become a major annoyance, removing the autostart file until this issue can be resolved.