AppImage custom excludelist x86: removed gnutls

Doesn't seem to be required and nwo (since the new PPA use) causes following error:
```
ultragrid_vidcap_rtsp.so: /lib/x86_64-linux-gnu/libgnutls.so.30: undefined symbol: nettle_siv_gcm_aes256_decrypt_message, version NETTLE_8
``
(obviously) when libgnutls30 is not installed, eg. in Ubuntu 24.04.

data/scripts/Linux-AppImage/excludelist.local.x86

@@ -1,5 +1,4 @@
 # Causes crash on U22.04 (see https://github.com/CESNET/UltraGrid/releases/download/v1.7/UltraGrid-1.7-x86_64.AppImage)
 libgdk-3.so.0
 # Rocky Linux 9
-libgnutls.so.30
 libgdk_pixbuf-2.0.so.0