Fix NVIDIA driver download for TrueNAS Scale Dragonfish

The previous fix had a few bugs. Because this is executed with `set -e`, the wget will cause the init process to fail if the url does not exist. Also, the github path was looking at an aarch64 download

Closes #156

overlay/etc/cont-init.d/60-configure_gpu_driver.sh

@@ -30,22 +30,29 @@ export amd_gpu_model="$(lspci | grep -i vga | grep -i amd)"
 
 
 function download_driver {
+    local driver_url
+    local stripped_version
+
     mkdir -p "${USER_HOME:?}/Downloads"
     chown -R ${USER:?} "${USER_HOME:?}/Downloads"
 
     if [[ ! -f "${USER_HOME:?}/Downloads/NVIDIA_${nvidia_host_driver_version:?}.run" ]]; then
         print_step_header "Downloading driver v${nvidia_host_driver_version:?}"
-        wget -q --show-progress --progress=bar:force:noscroll \
+        driver_url="http://download.nvidia.com/XFree86/Linux-x86_64/${nvidia_host_driver_version:?}/NVIDIA-Linux-x86_64-${nvidia_host_driver_version:?}.run"
-            -O /tmp/NVIDIA.run \
+        if wget --spider --quiet "${driver_url:?}"; then
-            "http://download.nvidia.com/XFree86/Linux-x86_64/${nvidia_host_driver_version:?}/NVIDIA-Linux-x86_64-${nvidia_host_driver_version:?}.run"
-        if [[ $? -gt 0 ]]; then
-            print_error "Unable to download driver from NVIDIA. Trying GitHub..."
-            # Strip the 'v' from the version if present (v545.23.08 -> 545.23.08)
-            local stripped_version="${nvidia_host_driver_version#v}"
             wget -q --show-progress --progress=bar:force:noscroll \
                 -O /tmp/NVIDIA.run \
-                "https://github.com/flathub/org.freedesktop.Platform.GL.nvidia/releases/download/cuda/NVIDIA-Linux-aarch64-${stripped_version}.run"
+                "${driver_url:?}"
-            if [[ $? -gt 0 ]]; then
+        else
+            print_warning "Unable to download driver from NVIDIA. Trying GitHub..."
+            # Strip the 'v' from the version if present (v545.23.08 -> 545.23.08)
+            stripped_version="${nvidia_host_driver_version#v}"
+            driver_url="https://github.com/flathub/org.freedesktop.Platform.GL.nvidia/releases/download/cuda/NVIDIA-Linux-x86_64-${stripped_version:?}.run"
+            if wget --spider --quiet "${driver_url:?}"; then
+                wget -q --show-progress --progress=bar:force:noscroll \
+                    -O /tmp/NVIDIA.run \
+                    "${driver_url:?}"
+            else
                 print_error "Unable to download driver from GitHub. Exit!"
                 return 1
             fi