Fixup building on rebar2

rebar.config

@@ -7,6 +7,10 @@
 ]}.
 
 {port_env, [
+    % Drop -lerl_interface
+    {"ERL_LDFLAGS", " -L$ERL_EI_LIBDIR -lei"},
+    {"win32", "ERL_LDFLAGS", " /LIBPATH:$ERL_EI_LIBDIR ei.lib"},
+
     {".*", "FLTO_FLAG", ""},
 
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin|gnu)",