On Turkish encoding "I" gets converted to ı, not 'i'.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@5769 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/model/BallColor.java

 package hudson.model;
 
+import java.util.Locale;
+
 /**
  * Ball color used for the build status indication.
  *
@@ -65,7 +67,7 @@ public enum BallColor {
      * Also used as a final name.
      */
     public String toString() {
-        return name().toLowerCase();
+        return name().toLowerCase(Locale.ENGLISH);
     }
 
     /**