Fix Issue 290: conduit-1.1 compatibility
When leksah-server is compiled as a system package with ghc 7.8.2 with other system packages such as conduit 1.1 that are built with transformers 0.4, then it is compiled with both transformers 0.3 as it uses GHC API, and with transforms 0.4 from the other system packages.  In this case it requires the liftIO instance.