improve a log message

src/main/java/jp/sf/fess/ds/impl/AbstractDataStoreImpl.java

@@ -131,7 +131,7 @@ public abstract class AbstractDataStoreImpl implements DataStore {
             }
             return value;
         } catch (final Exception e) {
-            logger.warn("Invalid value format: " + template, e);
+            logger.warn("Invalid value format: " + template + ", params: " + paramMap, e);
             return null;
         }
     }