Fix (open/closed) issue count when label excluded (#8815)

* Fix (open/closed) issue count when label excluded

* Use capital sql keywords

models/issue.go

@@ -1293,8 +1293,12 @@ func GetIssueStats(opts *IssueStatsOptions) (*IssueStats, error) {
 				log.Warn("Malformed Labels argument: %s", opts.Labels)
 			} else {
 				for i, labelID := range labelIDs {
+					if labelID > 0 {
 						sess.Join("INNER", fmt.Sprintf("issue_label il%d", i),
 							fmt.Sprintf("issue.id = il%[1]d.issue_id AND il%[1]d.label_id = %[2]d", i, labelID))
+					} else {
+						sess.Where("issue.id NOT IN (SELECT issue_id FROM issue_label WHERE label_id = ?)", -labelID)
+					}
 				}
 			}
 		}