fix: Select first upload library path by default. (#48)

This is just a minor fix. Probably it shouldn't make a big difference, but I think it is good style to make sure that the there is a pre-selected default for the upload library.

Reviewed-on: https://git.mills.io/prologic/tube/pulls/48
Co-authored-by: Heinrich 'Henrik' Langos <gumbo2000@noreply@mills.io>
Co-committed-by: Heinrich 'Henrik' Langos <gumbo2000@noreply@mills.io>

templates/upload.html

@@ -11,7 +11,7 @@
           <div class="upload-details">
             <select id="target-library-path" name="target-library-path">
 {{range $index, $item :=.Config.Library}}
-              <option value="{{$item.Path}}">{{$item.Path}}</option>
+              <option value="{{$item.Path}}"{{if eq $index 0}} selected{{end}}>{{$item.Path}}</option>
 {{end}}
             </select>
             <input id="video-title" type="text" placeholder="Optional title" />