eventmanager: fix params copy

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/common/eventmanager.go

@@ -584,6 +584,13 @@ func (p *EventParams) getACopy() *EventParams {
 		}
 		params.IDPCustomFields = &fields
 	}
+	if len(params.Metadata) > 0 {
+		metadata := make(map[string]string)
+		for k, v := range p.Metadata {
+			metadata[k] = v
+		}
+		params.Metadata = metadata
+	}
 
 	return &params
 }