apache-frontend: Unhardcode re6st validator url

  Not all frontend clusers setup uses the same re6stnet network.

software/apache-frontend/common.cfg

@@ -69,7 +69,7 @@ mode = 0644
 [template-apache-frontend]
 recipe = slapos.recipe.template
 url = ${:_profile_base_location_}/instance-apache-frontend.cfg
-md5sum = a245c933193f067457282c6e2c506191 
+md5sum = 92b69679b3004e160180504012a36f46
 output = ${buildout:directory}/template-apache-frontend.cfg
 mode = 0644
 

software/apache-frontend/instance-apache-frontend.cfg

@@ -104,6 +104,7 @@ configuration.extra_slave_instance_list =
 configuration.disk-cache-size = 8G
 configuration.trafficserver-autoconf-port = 8083
 configuration.trafficserver-mgmt-port = 8084
+configuration.re6st-verification-url = http://[2001:67c:1254:4::1]/index.html
 
 [frontend-configuration]
 template-log-access = ${template-log-access:target}
@@ -600,9 +601,6 @@ context =
 [monitor-verify-re6st-connectivity]
 recipe = slapos.cookbook:check_url_available
 path = $${directory:promise}/re6st-connectivity
-url = $${public:re6st-verification-url}
+url = $${instance-parameter:configuration.re6st-verification-url}
 dash_path = ${dash:location}/bin/dash
 curl_path = ${curl:location}/bin/curl
-
-[public]
-re6st-verification-url = http://[2001:67c:1254:4::1]/index.html

software/apache-frontend/instance-apache-input-schema.json

@@ -15,6 +15,11 @@
 			"type": "integer",
 			"default": 10
 		},		
+                "re6st-verification-url": {
+			"title": "Test Verification URL",
+			"description": "Url to verify if the internet and/or re6stnet is working.",
+			"type": "string"
+                },
 		"-frontend-authorized-slave-string": {
 			"title": "Authorized Slave String",
 			"description": "List of SOFTINST-XXX of Slaves, separated by space which is allowed to use custom configuration.",