internal/relui/templates: add missing baseLink

This fixes creation in a production environment.

For golang/go#47401

Change-Id: I9aa83e77b98c512c6efe75a30ecbb745aad5a1f4
Reviewed-on: https://go-review.googlesource.com/c/build/+/363978
Trust: Alexander Rakoczy <[email protected]>
Run-TryBot: Alexander Rakoczy <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>

Author: toothrot

internal/relui/templates/new_workflow.html

@@ -21,7 +21,7 @@ <h2>New Go Release</h2>
       </noscript>
     </form>
     {{if .Selected}}
-      <form action="/workflows/create" method="post">
+      <form action="{{baseLink "/workflows/create"}}" method="post">
         <input type="hidden" id="workflow.name" name="workflow.name" value="{{$.Name}}" />
         {{range $name := .Selected.ParameterNames}}
           <div class="NewWorkflow-Parameter">