Make opts truly optional

Author: wvu

lib/msf/core/exploit/cmdstager.rb

@@ -306,22 +306,22 @@ def compatible_flavor?(f)
   # overriden by a module this mixin.
   #
   # @param opts [Hash] Hash of configuration options.
-  def execute_cmdstager_begin(opts)
+  def execute_cmdstager_begin(opts = {})
   end
 
   # Code to execute after the cmd stager stub. This method is designed to be
   # overriden by a module this mixin.
   #
   # @param opts [Hash] Hash of configuration options.
-  def execute_cmdstager_end(opts)
+  def execute_cmdstager_end(opts = {})
   end
 
   # Code called to execute each command via an arbitrary module-defined vector.
   # This method needs to be overriden by modules using this mixin.
   #
   # @param cmd [String] The command to execute.
   # @param opts [Hash] Hash of configuration options.
-  def execute_command(cmd, opts)
+  def execute_command(cmd, opts = {})
     raise NotImplementedError
   end