Added better error handling for hCapthca

no issue

The errors returned by captcha validation shouldn't be visible to the
user, but should at least be accessible for the site owner.

ghost/captcha-service/lib/CaptchaService.js

@@ -61,8 +61,15 @@ class CaptchaService {
                 if (errorUtils.isGhostError(err)) {
                     return next(err);
                 } else {
+                    const message = 'Failed to verify hCaptcha token';
+
+                    logging.error(new InternalServerError({
+                        message,
+                        err
+                    }));
+
                     return next(new InternalServerError({
-                        message: 'Failed to verify hCaptcha token'
+                        message
                     }));
                 }
             }