Enable support for windows 8 in the exploit

Author: OJ

modules/exploits/windows/local/capcom_sys_exec.rb

@@ -51,7 +51,7 @@ def initialize(info={})
   end
 
   def check
-    if sysinfo['OS'] !~ /windows 7/i
+    if sysinfo['OS'] !~ /windows (7|8)/i
       return Exploit::CheckCode::Unknown
     end