Automatically clear stopwatch on merging a PR (#4327)

* Don't display buttons if there are no notices

* clear stopwatch on merging a PR

* remove redundant gt check

* use ctx.Flash as per @bkcsoft comment

* stop timer on closing issues/PRs too

* updated translation as per review

* redirect to login page after successfully activating account

* remove unrelated changes

* stop timer for issues that are closed via commits too..Not just the 'close' UI button

routers/repo/issue.go

@@ -1181,6 +1181,12 @@ func NewComment(ctx *context.Context, form auth.CreateCommentForm) {
 						return
 					}
 				} else {
+
+					if err := stopTimerIfAvailable(ctx.User, issue); err != nil {
+						ctx.ServerError("CreateOrStopIssueStopwatch", err)
+						return
+					}
+
 					log.Trace("Issue [%d] status changed to closed: %v", issue.ID, issue.IsClosed)
 
 					notification.NotifyIssueChangeStatus(ctx.User, issue, isClosed)