fix: check if debugtalk.go contains main() function

examples/demo-with-go-plugin/plugin/debugtalk_gen.go

@@ -0,0 +1,16 @@
+// NOTE: Generated By hrp v4.1.3, DO NOT EDIT!
+package main
+
+import (
+	"github.com/httprunner/funplugin/fungo"
+)
+
+func main() {
+	fungo.Register("SumTwoInt", SumTwoInt)
+	fungo.Register("SumInts", SumInts)
+	fungo.Register("Sum", Sum)
+	fungo.Register("SetupHookExample", SetupHookExample)
+	fungo.Register("TeardownHookExample", TeardownHookExample)
+	fungo.Register("GetUserAgent", GetUserAgent)
+	fungo.Serve()
+}