Filter empty errors from metrics data

Author: NonSwag

core/src/main/java/dev/faststats/core/SimpleMetrics.java

@@ -245,6 +245,7 @@ protected JsonObject createData() {
 
         getErrorTracker().map(SimpleErrorTracker.class::cast)
                 .map(SimpleErrorTracker::getData)
+                .filter(errors -> !errors.isEmpty())
                 .ifPresent(errors -> data.add("errors", errors));
         return data;
     }