Asciidoctor support again (#691)

Break another multi-valued conditional into two so Asciidoctor can use
it.

Author: nik9000

docs/versioned-plugins/include/6.x/input.asciidoc

@@ -151,7 +151,8 @@ a new input will not override the existing type. A type set at
 the shipper stays with that event for its life even
 when sent to another Logstash server.
 
-ifeval::["{type}"=="input" and "{plugin}"=="beats"]
+ifeval::["{type}"=="input"]
+ifeval::["{plugin}"=="beats"]
 
 ifeval::["{versioned_docs}"!="true"]
 NOTE: The Beats shipper automatically sets the `type` field on the event.
@@ -167,4 +168,5 @@ Logstash, it is ignored.
 endif::[]
 
 endif::[]
+endif::[]