lua randomseed per worker

rootfs/etc/nginx/lua/test/lua_ingress_test.lua

@@ -0,0 +1,9 @@
+describe("lua_ingress", function()
+  it("patches math.randomseed to not be called more than once per worker", function()
+    local s = spy.on(ngx, "log")
+
+    math.randomseed(100)
+    assert.spy(s).was_called_with(ngx.WARN,
+      string.format("ignoring math.randomseed(%d) since PRNG is already seeded for worker %d", 100, ngx.worker.pid()))
+  end)
+end)