use exception message. no method overload exists for log.severe

Author: ddavison

java/server/src/org/openqa/grid/internal/TestSession.java

@@ -561,7 +561,7 @@ public boolean sendDeleteSessionRequest() {
     } catch (Throwable e) {
       ok = false;
       // corrupted or the something else already sent the DELETE.
-      log.severe("Unable to send DELETE request for the current session", e);
+      log.severe("Unable to send DELETE request for the current session " + e.getMessage());
     } finally {
       try {
         EntityUtils.consume(responseBody);