UI: Use more subtle grey SHA1 labels

Current green SHA1 labels are more pronounced than other UI elements attracting
attention as if they were most important thing in the UI, while they are not as
important, especially without real Git client.

Using grey SHA1 labels makes the UI more balanced, less aggressive and lets
user to focus on other content elements.

NOTE: Neither GitHub or Bitbucket uses so heavy pronunciation as Gogs.

templates/repo/commits_table.tmpl

@@ -36,7 +36,7 @@
           {{end}}
         </td>
         <td class="message collapsing">
-          <a rel="nofollow" class="ui green sha label" href="{{AppSubUrl}}/{{$.Username}}/{{$.Reponame}}/commit/{{.ID}}">{{ShortSha .ID.String}}</a>
+          <a rel="nofollow" class="ui sha label" href="{{AppSubUrl}}/{{$.Username}}/{{$.Reponame}}/commit/{{.ID}}">{{ShortSha .ID.String}}</a>
           {{RenderCommitMessage .Summary $.RepoLink}}   
         </td>
         <td class="grey text right aligned">{{TimeSince .Author.When $.Lang}}</td>

templates/repo/view_list.tmpl

@@ -43,7 +43,7 @@
         </td>
         {{end}}
         <td class="message collapsing">
-          <a rel="nofollow" class="ui green sha label" href="{{AppSubUrl}}/{{$.Username}}/{{$.Reponame}}/commit/{{$commit.ID}}">{{ShortSha $commit.ID.String}}</a>
+          <a rel="nofollow" class="ui sha label" href="{{AppSubUrl}}/{{$.Username}}/{{$.Reponame}}/commit/{{$commit.ID}}">{{ShortSha $commit.ID.String}}</a>
           {{RenderCommitMessage $commit.Summary $.RepoLink}}
         </td>
         <td class="text grey right age">{{TimeSince $commit.Committer.When $.Lang}}</td>