[MCLEAN-104] Prevent NPE in fast mode and quiet build (#23)

diff --git a/src/main/java/org/apache/maven/plugins/clean/Cleaner.java b/src/main/java/org/apache/maven/plugins/clean/Cleaner.java
index 0434af5..5aa3225 100644
--- a/src/main/java/org/apache/maven/plugins/clean/Cleaner.java
+++ b/src/main/java/org/apache/maven/plugins/clean/Cleaner.java
@@ -441,7 +441,9 @@
                 }
                 if (!FAST_MODE_DEFER.equals(fastMode)) {
                     try {
-                        cleaner.logInfo.log("Waiting for background file deletion");
+                        if (cleaner.logInfo != null) {
+                            cleaner.logInfo.log("Waiting for background file deletion");
+                        }
                         while (status != STOPPED) {
                             wait();
                         }