static/frontend/vuln: hide introduced version if empty

For golang/go#48223

Change-Id: Id31f2584cef06ff018d0dcf8f0c7a6ff431d8545
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/379454
Trust: Jamal Carvalho <jamal@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
diff --git a/static/frontend/vuln/entry/entry.tmpl b/static/frontend/vuln/entry/entry.tmpl
index b7365ae..a0acbb0 100644
--- a/static/frontend/vuln/entry/entry.tmpl
+++ b/static/frontend/vuln/entry/entry.tmpl
@@ -43,7 +43,11 @@
         {{range .Affected}}
           <tr>
             <td><a href="/{{.Package.Name}}">{{.Package.Name}}</a></td>
-            <td>{{range .Ranges}}{{range .Events}}<div>{{.Introduced}}</div>{{end}}{{end}}</td>
+            <td>
+              {{range .Ranges}}{{range .Events}}
+                <div>{{if not (eq .Introduced "0")}}{{.Introduced}}{{end}}</div>
+              {{end}}{{end}}
+            </td>
             <td>{{range .Ranges}}{{range .Events}}<div>{{.Fixed}}</div>{{end}}{{end}}</td>
           </tr>
         {{end}}