Remove accidental characters in sample's pom.xml

See gh-651

Author: izeye

samples/rest-notes-spring-data-rest/pom.xml

@@ -86,7 +86,7 @@
 <logHandler>
 <outputToConsole>true</outputToConsole>
 <failIf>
-<severity>DEBUG</severity> (2)
+<severity>DEBUG</severity>
 </failIf>
 </logHandler>
 </configuration>