BUG/MINOR: httpclient/lua: missing pop for new timeout parameter

The lua timeout server lacks a lua_pop(), breaking the lua stack.

No backported needed.
diff --git a/src/hlua.c b/src/hlua.c
index 323a86b..8c7dc61 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -7251,6 +7251,7 @@
 		timeout = lua_tointeger(L, -1);
 		httpclient_set_timeout(hlua_hc->hc, timeout);
 	}
+	lua_pop(L, 1);
 
 	ret = lua_getfield(L, -1, "headers");
 	if (ret == LUA_TTABLE) {