Improve the guess_flavor logic to pull from module info

lib/msf/core/exploit/cmdstager.rb

@@ -226,11 +226,25 @@ module Exploit::CmdStager
     guess_flavor
   end
 
-  # Guess the cmd stager flavor to use using the target platform.
+  # Guess the cmd stager flavor to use using information from the module,
+  # target or platform.
   #
   # @return [Symbol] The cmd stager flavor to use.
   # @return [nil] if the cmd stager flavor can not be guessed.
   def guess_flavor
+    # First try to guess a compatible flavor based on the module & target information.
+    unless target_flavor.nil?
+      case target_flavor.class.to_s
+      when 'Array'
+        return target_flavor[0].to_sym
+      when 'String'
+        return target_flavor.to_sym
+      when 'Symbol'
+        return target_flavor
+      end
+    end
+
+    # Second try to guess a compatible flavor based on the target platform.
     return nil unless target_platform.names.length == 1
     c_platform = target_platform.names.first
     case c_platform