Update simple_backdoors_exec.rb

Updated the description

modules/exploits/multi/http/simple_backdoors_exec.rb

@@ -15,9 +15,9 @@ class Metasploit3 < Msf::Exploit::Remote
       'Name'           => 'Simple Backdoor Shell Remote Code Execution',
       'Description'    => %q{
           This module exploits unauthenticated simple web backdoor shells by leveraging the
-        common backdoor shell's CMD parameter  to execute commands. The SecLists project of
-        Daniel Miessler and Jason Haddix has a lot of samples for this kind of backdoor shells
-        which is categorized under Payloads.
+        common backdoor shells' CMD parameter  to execute commands. The SecLists project of
+        Daniel Miessler and Jason Haddix has a lot of samples for these kind of backdoor shells
+        which are categorized under Payloads.
       },
       'License'        => MSF_LICENSE,
       'Author'         =>