ok I just ran a test now and I got this in the www/butler.santiapps.com/logs/error.log:
2017/05/11 16:24:09 [error] 536#0: *5 connect() failed (113: No route to host) while connecting to upstream, client: 54.159.203.187, server: butler.santiapps.com, request: $
2017/05/11 16:24:09 [error] 536#0: *5 open() "/www/butler.santiapps.com/aism/50x.html" failed (2: No such file or directory), client: 54.159.203.187, server: butler.santiap$
2017/05/11 16:37:40 [error] 536#0: *7 connect() failed (113: No route to host) while connecting to upstream, client: 54.224.155.160, server: butler.santiapps.com, request: $
2017/05/11 16:37:40 [error] 536#0: *7 open() "/www/butler.santiapps.com/aism/50x.html" failed (2: No such file or directory), client: 54.224.155.160, server: butler.santiap$
2017/07/24 21:08:37 [error] 537#0: *3 connect() failed (111: Connection refused) while connecting to upstream, client: 139.162.113.204, server: butler.santiapps.com, reques$
2017/07/24 21:08:37 [error] 537#0: *3 open() "/www/butler.santiapps.com/50x.html" failed (2: No such file or directory), client: 139.162.113.204, server: butler.santiapps.c$
2017/07/25 04:50:49 [error] 537#0: *56 connect() failed (111: Connection refused) while connecting to upstream, client: 74.82.47.2, server: butler.santiapps.com, request: "$
2017/07/25 04:50:49 [error] 537#0: *56 open() "/www/butler.santiapps.com/50x.html" failed (2: No such file or directory), client: 74.82.47.2, server: butler.santiapps.com, $
2017/07/25 07:38:20 [error] 537#0: *68 connect() failed (111: Connection refused) while connecting to upstream, client: 185.35.63.147, server: butler.santiapps.com, request$
2017/07/25 07:38:20 [error] 537#0: *68 open() "/www/butler.santiapps.com/50x.html" failed (2: No such file or directory), client: 185.35.63.147, server: butler.santiapps.co$