Bug #254661 --> increase the default biff interval for RSS accounts.

mail/extensions/newsblog/rss.rdf

@@ -12,6 +12,7 @@
           <NC:nsIMsgIncomingServer>
             <NC:hostName>News &amp; Blogs</NC:hostName>
             <NC:type>rss</NC:type>
+            <NC:biffMinutes>45</NC:biffMinutes>
             <NC:username>nobody</NC:username>
           </NC:nsIMsgIncomingServer>
         </NC:incomingServer>