minor: remove unused variables in Connection and ReplSetConnection Classes

lib/mongo/connection.rb

@@ -542,16 +542,9 @@ module Mongo
       # Timeout on socket connect.
       @connect_timeout = opts[:connect_timeout] || nil
 
-      # Mutex for synchronizing pool access
-      # TODO: remove this.
-      @connection_mutex = Mutex.new
-
       # Global safe option. This is false by default.
       @safe = opts[:safe] || false
-
-      # Condition variable for signal and wait
-      @queue = ConditionVariable.new
-
+      
       # Connection pool for primay node
       @primary      = nil
       @primary_pool = nil

lib/mongo/repl_set_connection.rb

@@ -451,12 +451,6 @@ module Mongo
     def setup(opts)
       @safe_mutex_lock = Mutex.new
       @safe_mutexes = Hash.new {|hash, key| hash[key] = Mutex.new}
-
-      # Clean up connections to dead threads.
-      @last_cleanup = Time.now
-      @cleanup_lock = Mutex.new
-
-      @last_refresh = Time.now
       
       opts[:connect_timeout] = opts[:connect_timeout] || 30