fix npe on windows startup

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/HgPyFix.java

@@ -81,6 +81,8 @@ public class HgPyFix
    * @param config
    */
   public static void fixHgPy(SCMContextProvider context, HgConfig config)
+  {
+    if ((config != null) && config.isValid())
     {
       String basePath = context.getBaseDirectory().getAbsolutePath();
 
@@ -94,6 +96,12 @@ public class HgPyFix
         fixHgPy(file);
       }
     }
+    else if (logger.isDebugEnabled())
+    {
+      logger.debug(
+        "could not fix hg.py, because the configuration is not valid");
+    }
+  }
 
   /**
    * Visible for testing