[hotfix][build] Fix typo in parent pom

This closes #4947.

pom.xml

@@ -472,7 +472,7 @@ under the License.
 						<groupId>org.slf4j</groupId>
 						<artifactId>slf4j-log4j12</artifactId>
 					</exclusion>
-					<!-- Netty is only needed sor ZK servers, not clients -->
+					<!-- Netty is only needed for ZK servers, not clients -->
 					<exclusion>
 						<groupId>io.netty</groupId>
 						<artifactId>netty</artifactId>