Stop polluting the log with stacktraces. Fixes issue 7460

Author: barancev

java/server/src/org/openqa/selenium/remote/server/DefaultDriverSessions.java

@@ -99,9 +99,9 @@ private void registerDriver(Capabilities caps, String className) {
     try {
       registerDriver(caps, Class.forName(className).asSubclass(WebDriver.class));
     } catch (ClassNotFoundException e) {
-      log.log(Level.INFO, "Unable to register driver with className " + className + " - not be able to create due " + e.getMessage(), e);
+      log.log(Level.INFO, "Unable to register driver with className " + className + " due to ClassNotFoundException");
     } catch (NoClassDefFoundError e) {
-      log.log(Level.WARNING, "Unable to register driver with className " + className + " - dependency missing due " + e.getMessage(), e);
+      log.log(Level.WARNING, "Unable to register driver with className " + className + " due to NoClassDefFoundError");
     }
   }