fix ShutdownDisabledTest and LoggerContext_shutdownDisable changelog (#3581)

* - Modify the LoggerContext_shutdownDisable.xml file to change the entry type from "added" to "fixed"
- Update the ShutdownDisabledTest.java file to fix the assertion check for shutdown callback

* - Update the ShutdownDisabledTest.java file to fix the assertion check for shutdown callback

Author: Pluto-syd

log4j-core-test/src/test/java/org/apache/logging/log4j/core/ShutdownDisabledTest.java

@@ -35,6 +35,6 @@ void testShutdownFlag(final Configuration config, final LoggerContext ctx) throw
         Field shutdownCallback = LoggerContext.class.getDeclaredField("shutdownCallback");
         Object fieldValue = ReflectionUtil.getFieldValue(shutdownCallback, ctx);
         assertFalse(config.isShutdownHookEnabled(), "Shutdown hook is enabled");
-        assertNull(fieldValue, "Shutdown callback is null");
+        assertNull(fieldValue, "Shutdown callback");
     }
 }

src/changelog/.2.x.x/3508_LoggerContext_shutdownDisable.xml

@@ -2,7 +2,7 @@
 <entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="https://logging.apache.org/xml/ns"
        xsi:schemaLocation="https://logging.apache.org/xml/ns https://logging.apache.org/xml/ns/log4j-changelog-0.xsd"
-       type="added">
+       type="fixed">
     <issue id="2614" link="https://github.com/apache/logging-log4j2/issues/2614"/>
     <description format="asciidoc">
         Fix shutdownDisable configuration does not take effect