conf: Add router-dead-interval to conf

refs: #2277

Change-Id: Ie03159585f21fd1a1cf9d4d7f1f159b5e59a2269
diff --git a/nlsr.conf b/nlsr.conf
index 31d9633..2ddb1e4 100644
--- a/nlsr.conf
+++ b/nlsr.conf
@@ -11,6 +11,11 @@
   ; lsa-refresh-time is the time in seconds, after which router will refresh its LSAs
   lsa-refresh-time 1800      ; default value 1800. Valid values 240-7200
 
+  ; router-dead-interval is the time in seconds after which an inactive router's
+  ; LSAs are removed
+  ;router-dead-interval 3600 ; default value: 2*lsa-refresh-time. Value must be larger
+                             ; than lsa-refresh-time
+
   ; InterestLifetime (in seconds) for LSA fetching
   lsa-interest-lifetime 4    ; default value 4. Valid values 1-60
 
diff --git a/src/conf-file-processor.cpp b/src/conf-file-processor.cpp
index 9a100ec..3b6285b 100644
--- a/src/conf-file-processor.cpp
+++ b/src/conf-file-processor.cpp
@@ -281,13 +281,13 @@
     }
     else {
       std::cerr << "Value of router-dead-interval must be larger than lsa-refresh-time"
-        << std::endl;
+                << std::endl;
       return false;
     }
   }
   catch (const std::exception& ex) {
-    std::cerr << ex.what() << std::endl;
-    // non-critical error. default value is 2 * lsa-refresh-time
+    // Variable is optional so default value (2 * lsa-refresh-time) will be used;
+    // Continue processing file
   }
 
   try {