Update get_available_interfaces() to correctly filter loopback device (lo) (#6236)

automated install/basic-install.sh

@@ -574,7 +574,7 @@ Do you wish to continue with an IPv6-only installation?\\n\\n" \
 # Get available interfaces that are UP
 get_available_interfaces() {
     # There may be more than one so it's all stored in a variable
-    availableInterfaces=$(ip --oneline link show up | grep -v "lo" | awk '{print $2}' | cut -d':' -f1 | cut -d'@' -f1)
+    availableInterfaces=$(ip --oneline link show up | awk '{print $2}' |  grep -v "^lo" | cut -d':' -f1 | cut -d'@' -f1)
 }
 
 # A function for displaying the dialogs the user sees when first running the installer