protect against NPE on date not found in index page
diff --git a/src/main/java/org/apache/maven/dist/tools/index/DistCheckIndexPageMojo.java b/src/main/java/org/apache/maven/dist/tools/index/DistCheckIndexPageMojo.java
index 69c1ed7..6addfd2 100644
--- a/src/main/java/org/apache/maven/dist/tools/index/DistCheckIndexPageMojo.java
+++ b/src/main/java/org/apache/maven/dist/tools/index/DistCheckIndexPageMojo.java
@@ -155,7 +155,7 @@
         if ( displayDate )
         {
             sink.rawText( cipr.indexDate );
-            if ( isDateSimilar( cli.getReleaseDateFromMetadata(), cipr.indexDate ) )
+            if ( ( cipr.indexDate != null ) && isDateSimilar( cli.getReleaseDateFromMetadata(), cipr.indexDate ) )
             {
                 iconSuccess( sink );
             }