chore(elk): update nginx change mode to script for configuration reload

modules/elk/jobspec.nomad.hcl

@@ -405,13 +405,11 @@ job "elk" {
           }
           EOF
 
-        destination   = "local/nginx.conf"
+        destination = "local/nginx.conf"
-        change_mode   = "signal"
+        change_mode = "script"
-        change_signal = "SIGHUP"
+        change_script {
-
+          command = "/usr/sbin/nginx"
-        wait {
+          args    = ["-s", "reload"]
-          min = "5s"
-          max = "10s"
         }
       }