Fix example; server variable default and enum must be strings

Author: MikeRalphson

versions/3.0.md

@@ -386,10 +386,10 @@ The following shows how variables can be used for a server configuration:
         },
         "port": {
           "enum": [
-            8443,
-            443
+            "8443",
+            "443"
           ],
-          "default": 8443
+          "default": "8443"
         },
         "basePath": {
           "default": "v2"
@@ -411,9 +411,9 @@ servers:
       description: this value is assigned by the service provider, in this example `gigantic-server.com`
     port:
       enum:
-        - 8443
-        - 443
-      default: 8443
+        - '8443'
+        - '443'
+      default: '8443'
     basePath:
       # open meaning there is the opportunity to use special base paths as assigned by the provider, default is `v2`
       default: v2