Make variable name more specific

roles/webapi/defaults/main.yml

 ---
 
-api_port: 443
+argo_web_api_port: 443
 cors_support: "false"

roles/webapi/templates/argo-web-api.conf.j2

 [server]
 bindip = ""
-port = {{ api_port }}
+port = {{ argo_web_api_port }}
 maxprocs = 4
 cache = false
 lrucache = 700000000
@@ -13,4 +13,4 @@ enablecors = {{ cors_support }}
 [mongodb]
 host = "127.0.0.1"
 port = 27017
-db = "argo_core"
\ No newline at end of file
+db = "argo_core"