Modfiy casing in JVM home log message

This makes the log message consistent with the following line that shows
the JVM arguments.

Author: jasontedor

server/src/main/java/org/elasticsearch/node/Node.java

@@ -291,7 +291,7 @@ protected Node(
                 Constants.JVM_NAME,
                 Constants.JAVA_VERSION,
                 Constants.JVM_VERSION);
-            logger.info("JVM Home [{}]", System.getProperty("java.home"));
+            logger.info("JVM home [{}]", System.getProperty("java.home"));
             logger.info("JVM arguments {}", Arrays.toString(jvmInfo.getInputArguments()));
             if (Build.CURRENT.isProductionRelease() == false) {
                 logger.warn(