Change the default urgency setting to medium

But don't force urgency to medium for new packages, they can still be
low.

Signed-off-by: Julien Cristau <jcristau@debian.org>

britney.conf

@@ -33,7 +33,7 @@ MINDAYS_MEDIUM    = 5
 MINDAYS_HIGH      = 2
 MINDAYS_CRITICAL  = 0
 MINDAYS_EMERGENCY = 0
-DEFAULT_URGENCY   = low
+DEFAULT_URGENCY   = medium
 
 # hint permissions
 HINTS_ABA         = ALL

britney.py

@@ -1239,7 +1239,8 @@ class Britney(object):
 
         # retrieve the urgency for the upload, ignoring it if this is a NEW package (not present in testing)
         urgency = self.urgencies.get(src, self.options.default_urgency)
-        if not source_t and urgency != self.options.default_urgency:
+        if not source_t:
+            if self.MINDAYS[urgency] < self.MINDAYS[self.options.default_urgency]:
                 excuse.addhtml("Ignoring %s urgency setting for NEW package" % (urgency))
                 urgency = self.options.default_urgency