bugtracker.md: fix duplicate title

Author: avarga

bugtracker.md

@@ -1,8 +1,7 @@
 ---
 layout: page
-title: Reporting bugs in OMNeT++
+title: Reporting Bugs in OMNeT++
 ---
-# Reporting bugs in OMNeT++
 
 To report a bug or suggest an enhancement, log in to the OMNeT++
 Bugtracker, and click Report Issue. Create an account if you do not have

mailing-list.md

@@ -1,8 +1,7 @@
 ---
 layout: page
-title: Mailing list
+title: Mailing List
 ---
-# Mailing list
 
 The mailing list is a place where you can ask for help, share your ideas, etc. This is a googlegroups mailing list which is 
 **[archived here](http://groups.google.com/group/omnetpp/topics)**.