go: 1.4: disable failing test in sandbox

pkgs/development/compilers/go/1.4.nix

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     sed -i 's,/bin/pwd,'"`type -P pwd`", src/os/os_test.go
     # Disable the unix socket test
     sed -i '/TestShutdownUnix/areturn' src/net/net_test.go
+    # Disable network timeout test
+    sed -i '/TestDialTimeout/areturn' src/net/dial_test.go
     # Disable the hostname test
     sed -i '/TestHostname/areturn' src/os/os_test.go
     # ParseInLocation fails the test