Bump github.com/prometheus/alertmanager from 0.24.0 to 0.25.1

Bumps [github.com/prometheus/alertmanager](https://github.com/prometheus/alertmanager) from 0.24.0 to 0.25.1.
- [Release notes](https://github.com/prometheus/alertmanager/releases)
- [Changelog](https://github.com/prometheus/alertmanager/blob/v0.25.1/CHANGELOG.md)
- [Commits](https://github.com/prometheus/alertmanager/compare/v0.24.0...v0.25.1)

---
updated-dependencies:
- dependency-name: github.com/prometheus/alertmanager
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/prometheus/alertmanager/template/email.html

@@ -325,13 +325,17 @@ a {
           <tr>
             {{ if gt (len .Alerts.Firing) 0 }}
             <td class="alert alert-warning">
+              {{ .Alerts | len }} alert{{ if gt (len .Alerts) 1 }}s{{ end }} for {{ range .GroupLabels.SortedPairs }}
+                {{ .Name }}={{ .Value }}
+              {{ end }}
+            </td>
             {{ else }}
             <td class="alert alert-good">
-            {{ end }}
               {{ .Alerts | len }} alert{{ if gt (len .Alerts) 1 }}s{{ end }} for {{ range .GroupLabels.SortedPairs }}
                 {{ .Name }}={{ .Value }} 
               {{ end }}
             </td>
+            {{ end }}
           </tr>
           <tr>
             <td class="content-wrap">