Add load_resource exception for msfconsole.rc

This prevents msfconsole from erroring on a nonexistent msfconsole.rc.

lib/msf/ui/console/command_dispatcher/core.rb

@@ -243,16 +243,16 @@ class Core
 
     args.each do |res|
       good_res = nil
-      if (File.file? res and File.readable? res)
+      if ::File.exists?(res)
         good_res = res
       elsif
         # let's check to see if it's in the scripts/resource dir (like when tab completed)
         [
-          ::Msf::Config.script_directory + File::SEPARATOR + "resource",
-          ::Msf::Config.user_script_directory + File::SEPARATOR + "resource"
+          ::Msf::Config.script_directory + ::File::SEPARATOR + "resource",
+          ::Msf::Config.user_script_directory + ::File::SEPARATOR + "resource"
         ].each do |dir|
-          res_path = dir + File::SEPARATOR + res
-          if (File.file?(res_path) and File.readable?(res_path))
+          res_path = dir + ::File::SEPARATOR + res
+          if ::File.exists?(res_path)
             good_res = res_path
             break
           end

lib/msf/ui/console/driver.rb

@@ -235,7 +235,8 @@ class Driver < Msf::Ui::Driver
     # Process any resource scripts
     if opts['Resource'].blank?
       # None given, load the default
-      load_resource(File.join(Msf::Config.config_directory, 'msfconsole.rc'))
+      default_resource = ::File.join(Msf::Config.config_directory, 'msfconsole.rc')
+      load_resource(default_resource) if ::File.exists?(default_resource)
     else
       opts['Resource'].each { |r|
         load_resource(r)
@@ -420,7 +421,7 @@ class Driver < Msf::Ui::Driver
     if path == '-'
       resource_file = $stdin.read
       path = 'stdin'
-    elsif ::File.readable?(path)
+    elsif ::File.exists?(path)
       resource_file = ::File.read(path)
     else
       print_error("Cannot find resource script: #{path}")