g3proxy: default to use yaml conf file extension

g3proxy/examples/simple_sni_proxy/g3proxy.yaml

@@ -0,0 +1,32 @@
+---
+runtime:
+  thread_number: 2
+
+log: journal
+
+controller:
+  local:
+    recv_timeout: 30
+    send_timeout: 1
+
+server:
+  - name: test
+    escaper: default
+    type: sni_proxy
+    listen:
+      address: "[::]:443"
+    conn_limit: 100M
+
+resolver:
+  - name: default
+    type: c-ares
+    server: 223.5.5.5
+
+escaper:
+  - name: default
+    type: direct_fixed
+    no_ipv6: true
+    resolver: default
+    resolve_strategy: IPv4Only
+    tcp_conn_limit: 80M
+    udp_relay_limit: 10M