Corrected the typos in upgrade.html
Reviewers: Jakob Homan Jason Gustafson
<li>Bumping the protocol version and restarting can be done any time after the brokers are upgraded. It does not have to be immediately after.
Similarly for the message format version.</li>
<li>If you are using Java8 method references in your Kafka Streams code you might need to update your code to resolve method ambiguties.
- Hot-swaping the jar-file only might not work.</li>
+ Hot-swapping the jar-file only might not work.</li>
</ol>
<h5><a id="upgrade_120_notable" href="#upgrade_120_notable">Notable changes in 1.2.0</a></h5>
<li>Bumping the protocol version and restarting can be done any time after the brokers are upgraded. It does not have to be immediately after.
Similarly for the message format version.</li>
<li>If you are using Java8 method references in your Kafka Streams code you might need to update your code to resolve method ambiguties.
- Hot-swaping the jar-file only might not work.</li>
+ Hot-swapping the jar-file only might not work.</li>
</ol>
