only set log_level in the Metasploit Framework context

when including framework as a gem, this app is undefined

MS-1518

Author: Brent Cook

config/environments/production.rb

@@ -1,3 +1,5 @@
-Metasploit::Framework::Application.configure do
-  config.log_level = :info
+if defined? Metasploit::Framework::Application
+  Metasploit::Framework::Application.configure do
+    config.log_level = :info
+  end
 end