britney: add ignore-rc-bugs hint to HINTS_HELPERS

Signed-off-by: Niels Thykier <niels@thykier.net>

britney.py

@@ -239,7 +239,8 @@ class Britney(object):
     For more documentation on this script, please read the Developers Reference.
     """
 
-    HINTS_HELPERS = ("easy", "hint", "remove", "block", "block-udeb", "unblock", "unblock-udeb", "approve", "remark", "ignore-piuparts")
+    HINTS_HELPERS = ("easy", "hint", "remove", "block", "block-udeb", "unblock", "unblock-udeb", "approve",
+                     "remark", "ignore-piuparts", "ignore-rc-bugs")
     HINTS_STANDARD = ("urgent", "age-days") + HINTS_HELPERS
     # ALL = {"force", "force-hint", "block-all"} | HINTS_STANDARD | registered policy hints (not covered above)
     HINTS_ALL = ('ALL')