Merge pull request #1294 from input-output-hk/lc/exe-threaded

enable -threaded on hydra-explorer exe

hydra-explorer/hydra-explorer.cabal

@@ -40,7 +40,6 @@ common project-config
 
 library
   import:          project-config
-  ghc-options:     -threaded -rtsopts -with-rtsopts=-N
   hs-source-dirs:  src
   ghc-options:     -haddock
   build-depends:
@@ -63,6 +62,7 @@ library
 executable hydra-explorer
   import:         project-config
   hs-source-dirs: exe
+  ghc-options:    -threaded -rtsopts -with-rtsopts=-N
   main-is:        Main.hs
   build-depends:
     , hydra-explorer