Merge pull request #771 from rustygeldmacher/remove_unneeded_conditional

Removed unnecessary conditional in `call!`

Author: dblock

lib/grape/endpoint.rb

@@ -188,7 +188,7 @@ def call!(env)
         options[:app].call(env)
       else
         builder = build_middleware
-        builder.run options[:app] || lambda { |arg| run(arg) }
+        builder.run lambda { |arg| run(arg) }
         builder.call(env)
       end
     end