Fix NPE to use Http11NioProtocol handler with default parameters!

Fix NPE to use Http11NioProtocol handler with default parameters!
# example:
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
        maxThreads="150" minSpareThreads="4"/>
<Connector executor="tomcatThreadPool"
               port="8080" protocol="org.apache.coyote.http11.Http11NioProtocol"
               connectionTimeout="20000"
               redirectPort="8443" />

Used at MAC OS X with "-Djava.net.preferIPv4Stack=true"

I am not sure that default returns are correct!

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@712278 13f79535-47bb-0310-9956-ffa450edef68