MINOR: Fix doc format in upgrade notes
Author: hejiefang
Reviewers: Srinivas Manikumar Reddy
Closes from hejiefang/modifynotable
<li><a href="https://cwiki.apache.org/confluence/x/oYtjB">KIP-186</a> increases the default offset retention time from 1 day to 7 days. This makes it less likely to "lose" offsets in an application that commits infrequently. It also increases the active set of offsets and therefore can increase memory usage on the broker. Note that the console consumer currently enables offset commit by default and can be the source of a large number of offsets which this change will now preserve for 7 days instead of 1. You can preserve the existing behavior by setting the broker config <code>offsets.retention.minutes</code> to 1440.</li>
<li>Support for Java 7 has been dropped, Java 8 is now the minimum version required.</li>
<li> The default value for <code>ssl.endpoint.identification.algorithm</code> was changed to <code>https</code>, which performs hostname verification (man-in-the-middle attacks are possible otherwise). Set <code>ssl.endpoint.identification.algorithm</code> to an empty string to restore the previous behaviour. </li>
- <li><a href="https://issues.apache.org/jira/browse/KAFKA-5674">KAFKA-5674</a> extends the lower interval of <code>max.connections.per.ip minimum</code> to zero and therefore allows IP-based filtering of inbound connections.</li>
+ <li><a href="https://issues.apache.org/jira/browse/KAFKA-5674">KAFKA-5674</a> extends the lower interval of <code>max.connections.per.ip</code> minimum to zero and therefore allows IP-based filtering of inbound connections.</li>
<li><a href="https://cwiki.apache.org/confluence/display/KAFKA/KIP-272%3A+Add+API+version+tag+to+broker%27s+RequestsPerSec+metric">KIP-272</a>
added API version tag to the metric <code>kafka.network:type=RequestMetrics,name=RequestsPerSec,request={Produce|FetchConsumer|FetchFollower|...}</code>.
This metric now becomes <code>kafka.network:type=RequestMetrics,name=RequestsPerSec,request={Produce|FetchConsumer|FetchFollower|...},version={0|1|2|3|...}</code>. This will impact
