don't mark bugs as stale

Author: Kristján Oddsson

.github/stale.yml

@@ -3,9 +3,8 @@ daysUntilStale: 60
 # Number of days of inactivity before a stale issue is closed
 daysUntilClose: 7
 # Issues with these labels will never be considered stale
-#exemptLabels:
-#  - pinned
-#  - security
+exemptLabels:
+  - bug
 # Label to use when marking an issue as stale
 staleLabel: wontfix
 # Comment to post when marking an issue as stale. Set to `false` to disable