fix: Generate at most one server directive per container

test/test_multiple-networks.yml

@@ -3,6 +3,8 @@ version: '2'
 networks:
   net1: {}
   net2: {}
+  net3a: {}
+  net3b: {}
 
 services:
   nginx-proxy:
@@ -12,6 +14,8 @@ services:
     networks:
       - net1
       - net2
+      - net3a
+      - net3b
 
   web1:
     image: web
@@ -32,3 +36,14 @@ services:
       VIRTUAL_HOST: web2.nginx-proxy.local
     networks:
       - net2
+
+  web3:
+    image: web
+    expose:
+      - "83"
+    environment:
+      WEB_PORTS: 83
+      VIRTUAL_HOST: web3.nginx-proxy.test
+    networks:
+      - net3a
+      - net3b