Improved enum parsing.

src/fr/devinsy/statoolinfos/core/Configuration.java

@@ -385,7 +385,16 @@ public class Configuration extends PathPropertyList
     {
         ProbeMode result;
 
-        result = ProbeMode.valueOf(StringUtils.upperCase(get("conf.probe.mode")));
+        String value = get("conf.probe.mode");
+
+        if (StringUtils.isBlank(value))
+        {
+            result = null;
+        }
+        else
+        {
+            result = ProbeMode.valueOf(StringUtils.upperCase(value));
+        }
 
         //
         return result;