Disable setting the jobs: $nprocs line in default ~/.cabal config

It breaks for fresh installs with users who have Cabal-1.6.0
rather than Cabal-1.6.0.1, ie users of ghc-7.6.1.

cabal-install/Distribution/Client/Config.hs

@@ -203,7 +203,7 @@ initialSavedConfig = do
     savedInstallFlags    = mempty {
       installSummaryFile = [toPathTemplate (logsDir </> "build.log")],
       installBuildReports= toFlag AnonymousReports,
-      installNumJobs     = toFlag (Just numberOfProcessors)
+      --installNumJobs     = toFlag (Just numberOfProcessors)
     }
   }