Revert the api change and deprecated nullArg as it's a deviation from…

… the official protocol

Signed-off-by: Paulo Lopes <pmlopes@gmail.com>

src/main/java/io/vertx/redis/client/RedisOptions.java

@@ -377,6 +377,9 @@ public int getPoolCleanerInterval() {
   /**
    * Tune how often in milliseconds should the connection pool cleaner execute.
    *
+   * For each connection in the pool, connections marked as invalid will be forcibly closed. A connection is marked
+   * invalid if it enters a exception or fatal state.
+   *
    * @param poolCleanerInterval the interval in milliseconds (-1 for never)
    * @return fluent self.
    */

src/main/java/io/vertx/redis/client/Request.java

@@ -218,6 +218,9 @@ default Request arg(JsonArray arg) {
   }
 
   /**
+   * @deprecated REDIS does not support {@code null} as a parameter, only as response. This was a deviation from the
+   * official protocol which should be avoided. Other clients explicitly do not allow this.
+   *
    * Adds a {@code null} encoded string. Redis does not allow storing the {@code null} value by itself. This method
    * will encode any null value as the four character long string {@code "null"}.
    *
@@ -227,6 +230,7 @@ default Request arg(JsonArray arg) {
    * @return self
    */
   @Fluent
+  @Deprecated
   Request nullArg();
 
   /**