Fixed caddy reverse proxy for gRPC (#82)

* Fixed caddy reverse proxy for gRPC

* Fixed tab/space

Trojan-gRPC-Caddy2／Nginx/Caddyfile

@@ -1,9 +1,13 @@
 example.com {
-    @grpc {
-        protocol grpc
-        path  # 填写 /你的 ServiceName/*
-    }
-    reverse_proxy @grpc unix//dev/shm/Xray-Trojan-gRPC.socket
-    root * /var/www
-    file_server
+	@grpc {
+		protocol grpc
+		path  # 填写 /你的 ServiceName/*
+	}
+	reverse_proxy @grpc unix//dev/shm/Xray-Trojan-gRPC.socket {
+		transport http {
+			versions h2c
+		}
+	}
+	root * /var/www
+	file_server
 }