Remove the commented line of overriding ${catalina.base}/conf/hst.properties in container's context.xml

By the fix of HSTTWO-2422, if ${catalina.base}/conf/hst.properties exists, then it is automatically picked up and can override the other default configuration files. [1]
Therefore, we don't have to keep the commented hst.properties configuration line in the conf/context.xml any more.

Specifically, we can safely remove the following lines:

<!--
<Parameter name="hst-config-properties" value="file:${catalina.base}/conf/hst.properties" override="false"/>
-->

[1] http://www.onehippo.org/7_8/library/concepts/web-application/hst-2-container-configuration.html