3.x: Javadoc: Fix wording of *OnSubscribe interfaces

src/main/java/io/reactivex/rxjava3/core/CompletableOnSubscribe.java

@@ -17,7 +17,7 @@
 
 /**
  * A functional interface that has a {@code subscribe()} method that receives
- * an instance of a {@link CompletableEmitter} instance that allows pushing
+ * a {@link CompletableEmitter} instance that allows pushing
  * an event in a cancellation-safe manner.
  */
 @FunctionalInterface

src/main/java/io/reactivex/rxjava3/core/FlowableOnSubscribe.java

@@ -17,7 +17,7 @@
 
 /**
  * A functional interface that has a {@code subscribe()} method that receives
- * an instance of a {@link FlowableEmitter} instance that allows pushing
+ * a {@link FlowableEmitter} instance that allows pushing
  * events in a backpressure-safe and cancellation-safe manner.
  *
  * @param <T> the value type pushed

src/main/java/io/reactivex/rxjava3/core/MaybeOnSubscribe.java

@@ -17,7 +17,7 @@
 
 /**
  * A functional interface that has a {@code subscribe()} method that receives
- * an instance of a {@link MaybeEmitter} instance that allows pushing
+ * a {@link MaybeEmitter} instance that allows pushing
  * an event in a cancellation-safe manner.
  *
  * @param <T> the value type pushed

src/main/java/io/reactivex/rxjava3/core/ObservableOnSubscribe.java

@@ -17,7 +17,7 @@
 
 /**
  * A functional interface that has a {@code subscribe()} method that receives
- * an instance of an {@link ObservableEmitter} instance that allows pushing
+ * an {@link ObservableEmitter} instance that allows pushing
  * events in a cancellation-safe manner.
  *
  * @param <T> the value type pushed

src/main/java/io/reactivex/rxjava3/core/SingleOnSubscribe.java

@@ -17,7 +17,7 @@
 
 /**
  * A functional interface that has a {@code subscribe()} method that receives
- * an instance of a {@link SingleEmitter} instance that allows pushing
+ * a {@link SingleEmitter} instance that allows pushing
  * an event in a cancellation-safe manner.
  *
  * @param <T> the value type pushed