modify stale config

Author: jpoehnelt

.github/stale.yml

@@ -1,7 +1,7 @@
 # Configuration for probot-stale - https://github.com/probot/stale
 
 # Number of days of inactivity before an Issue or Pull Request becomes stale
-daysUntilStale: 30
+daysUntilStale: 90
 
 # Number of days of inactivity before an Issue or Pull Request with the stale label is closed.
 # Set to false to disable. If disabled, issues still need to be closed manually, but will remain marked as stale.