Ensure compression (lz4) support when building from src

rebar.config.script

@@ -1,4 +1,11 @@
 %% -*- erlang-mode -*-
+case os:getenv("ERLANG_ROCKSDB_OPTS") of
+    false ->
+        true = os:putenv("ERLANG_ROCKSDB_OPTS", "-DWITH_BUNDLE_LZ4=ON");
+    _ ->
+        %% If manually set, we assume it's throught through
+        skip
+end.
 case os:getenv("DEBUG") of
     "true" ->
 	Opts = proplists:get_value(erl_opts, CONFIG, []),