[SPARK-21126] The configuration which named "spark.core.connection.auth.wait.timeout" hasn't been used in spark
[SPARK-21126] The configuration which named "spark.core.connection.auth.wait.timeout" hasn't been used in spark

[https://issues.apache.org/jira/browse/SPARK-21126](https://issues.apache.org/jira/browse/SPARK-21126)
The configuration which named "spark.core.connection.auth.wait.timeout" hasn't been used in spark,so I think it should be removed from configuration.md.

Author: liuzhaokun <liu.zhaokun@zte.com.cn>

Closes #18333 from liu-zhaokun/new3.

(cherry picked from commit 0d8604bb849b3370cc21966cdd773238f3a29f84)
Signed-off-by: Sean Owen <291c18f3fb7528c712d9098b0e50a515ea0b91d5@cloudera.com>

apache-spark-on-k8s/spark,publicRoman/spark,publicRoman/spark,jlopezmalla/spark,apache-spark-on-k8s/spark,jlopezmalla/spark,jlopezmalla/spark,jlopezmalla/spark,apache-spark-on-k8s/spark,publicRoman/spark,apache-spark-on-k8s/spark,apache-spark-on-k8s/spark,jlopezmalla/spark,jlopezmalla/spark,publicRoman/spark,publicRoman/spark,publicRoman/spark,apache-spark-on-k8s/spark,apache-spark-on-k8s/spark,jlopezmalla/spark,publicRoman/spark