fixed after review

Author: denizkilic

api/src/main/java/com/messagebird/objects/ErrorReport.java

@@ -27,7 +27,7 @@ public ErrorReport(Integer code, String description, String parameter, String me
     @Override
     public String toString() {
         String str =  "ErrorReport{code=" + code;
-        if (message != null) {
+        if (message != null && !message.isEmpty()) {
             str = str.concat(", message='" + message + "'");
         } else {
             str = str.concat(", description='" + description + "'");