Land rapid7#8433, Fix proxy_type references to handle nil case

Author: wwebb-r7

lib/rex/payloads/meterpreter/config.rb

@@ -86,7 +86,7 @@ def transport_block(opts)
       proxy_host = ''
       if opts[:proxy_host] && opts[:proxy_port]
         prefix = 'http://'
-        prefix = 'socks=' if opts[:proxy_type].downcase == 'socks'
+        prefix = 'socks=' if opts[:proxy_type].to_s.downcase == 'socks'
         proxy_host = "#{prefix}#{opts[:proxy_host]}:#{opts[:proxy_port]}"
       end
       proxy_host = to_str(proxy_host || '', PROXY_HOST_SIZE)

lib/rex/post/meterpreter/client_core.rb

@@ -730,7 +730,7 @@ def transport_prepare_request(method, opts={})
 
       if opts[:proxy_host] && opts[:proxy_port]
         prefix = 'http://'
-        prefix = 'socks=' if opts[:proxy_type] == 'socks'
+        prefix = 'socks=' if opts[:proxy_type].to_s.downcase == 'socks'
         proxy = "#{prefix}#{opts[:proxy_host]}:#{opts[:proxy_port]}"
         request.add_tlv(TLV_TYPE_TRANS_PROXY_HOST, proxy)