Reduce logging level for non-critical warning

spring-bootstrap/src/main/java/org/springframework/bootstrap/StartupInfoLogger.java

@@ -34,6 +34,7 @@ import org.springframework.util.StringUtils;
  * Logs application information on startup.
  * 
  * @author Phillip Webb
+ * @author Dave Syer
  */
 class StartupInfoLogger {
 

spring-bootstrap/src/main/java/org/springframework/bootstrap/context/embedded/AbstractEmbeddedServletContainerFactory.java

@@ -313,7 +313,7 @@ public abstract class AbstractEmbeddedServletContainerFactory implements
 		file = file != null ? file : getWarFileDocumentRoot();
 		file = file != null ? file : getCommonDocumentRoot();
 		if (file == null && this.logger.isWarnEnabled()) {
-			this.logger.warn("None of the document roots "
+			this.logger.debug("None of the document roots "
 					+ Arrays.asList(COMMON_DOC_ROOTS)
 					+ " point to a directory and will be ignored.");
 		}