Update java-filter-plugin.md

Remove unusual Unicode

Author: ash-darin

docs/extend/java-filter-plugin.md

@@ -165,10 +165,10 @@ public Collection<Event> filter(Collection<Event> events, FilterMatchListener ma
 
 Finally, we come to the `filter` method that is invoked by the Logstash execution engine on batches of events as they flow through the event processing pipeline. The events to be filtered are supplied in the `events` argument and the method should return a collection of filtered events. Filters may perform a variety of actions on events as they flow through the pipeline including:
 
-* Mutation — Fields in events may be added, removed, or changed by a filter. This is the most common scenario for  filters that perform various kinds of enrichment on events. In this scenario, the incoming `events` collection may be returned unmodified since the events in the collection are mutated in place.
-* Deletion — Events may be removed from the event pipeline by a filter so that subsequent filters and outputs  do not receive them. In this scenario, the events to be deleted must be removed from the collection of filtered events before it is returned.
-* Creation — A filter may insert new events into the event pipeline that will be seen only by subsequent filters and outputs. In this scenario, the new events must be added to the collection of filtered events before it is returned.
-* Observation — Events may pass unchanged by a filter through the event pipeline. This may be useful in scenarios where a filter performs external actions (e.g., updating an external cache) based on the events observed in the event pipeline. In this scenario, the incoming `events` collection may be returned unmodified since no changes were made.
+* Mutation - Fields in events may be added, removed, or changed by a filter. This is the most common scenario for  filters that perform various kinds of enrichment on events. In this scenario, the incoming `events` collection may be returned unmodified since the events in the collection are mutated in place.
+* Deletion - Events may be removed from the event pipeline by a filter so that subsequent filters and outputs  do not receive them. In this scenario, the events to be deleted must be removed from the collection of filtered events before it is returned.
+* Creation - A filter may insert new events into the event pipeline that will be seen only by subsequent filters and outputs. In this scenario, the new events must be added to the collection of filtered events before it is returned.
+* Observation - Events may pass unchanged by a filter through the event pipeline. This may be useful in scenarios where a filter performs external actions (e.g., updating an external cache) based on the events observed in the event pipeline. In this scenario, the incoming `events` collection may be returned unmodified since no changes were made.
 
 In the example above, the value of the `source` field is retrieved from each event and reversed if it is a string value. Because each event is mutated in place, the incoming `events` collection can be returned.