fix issue: Windows Platform did not handle process signal (#3154)

net/ghttp/ghttp_server_admin_windows.go

@@ -9,7 +9,19 @@
 
 package ghttp
 
-// registerSignalHandler does nothing on window platform.
-func handleProcessSignal() {
+import (
+	"context"
+	"os"
 
+	"github.com/gogf/gf/v2/os/gproc"
+)
+
+// handleProcessSignal handles all signals from system in blocking way.
+func handleProcessSignal() {
+	var ctx = context.TODO()
+	gproc.AddSigHandlerShutdown(func(sig os.Signal) {
+		shutdownWebServersGracefully(ctx, sig)
+	})
+
+	gproc.Listen()
 }