use max instead of sort_by { |p| p.size }.last

`sort_by { |p| p.size }.last` is less readable compared to just using the `max` method

I believe this does basicall the exact same thing, ontop of being much faster in my micro benchmark.

The old method was, something like, 8 times slower.

lib/msf/core/auxiliary/web.rb

@@ -259,7 +259,7 @@ module Auxiliary::Web
       if payloads
         payload = payloads.select { |p|
           element.altered_value.include?( p )
-        }.sort_by { |p| p.size }.last
+        }.max
       end
     end
 

lib/msf/core/auxiliary/web/analysis/timing.rb

@@ -55,8 +55,7 @@ module Analysis::Timing
       timeout = opts[:delay]
 
       seed    = p.altered_value.dup
-      payload = fuzzer.payloads.select{ |pl| seed.include?( pl ) }.
-        sort_by { |p2| p2.size }.last
+      payload = fuzzer.payloads.select{ |pl| seed.include?( pl ) }.max
 
       # 1st pass, make sure the webapp is responsive
       if_responsive do