Fix type for HAProxy health.last field

CHANGELOG.asciidoc

@@ -47,6 +47,7 @@ https://github.com/elastic/beats/compare/v6.0.0-alpha1...master[Check the HEAD d
 - Add filtering to system filesystem metricset to remove relative mountpoints like those
   from Linux network namespaces. {pull}4370[4370]
 - Remove unnecessary print statement in schema apis {pull}4355[4355]
+- Fix type of field `haproxy.stat.check.health.last`. {issue}4407[4407]
 
 *Packetbeat*
 - Enable memcache filtering only if a port is specified in the config file. {issue}4335[4335]

metricbeat/docs/fields.asciidoc

@@ -5188,15 +5188,17 @@ Time in ms that it took to finish the last health check.
 [float]
 === haproxy.stat.check.health.last
 
-type: long
+type: keyword
 
+The result of the last health check.
 
 
 [float]
 === haproxy.stat.check.health.fail
 
 type: long
 
+Number of failed checks.
 
 
 [float]

metricbeat/module/haproxy/stat/_meta/fields.yml

@@ -298,12 +298,14 @@
             Time in ms that it took to finish the last health check.
 
         - name: health.last
-          type: long
+          type: keyword
           description: >
+            The result of the last health check.
 
         - name: health.fail
           type: long
           description: >
+            Number of failed checks.
 
         - name: agent.last
           type: integer