Merge pull request #4 from secureCodeBox/fix/null-mitigation

Remove incorrect @nonnull annotation from mitigation field

Author: wurstbrot

src/main/java/io/securecodebox/persistence/defectdojo/models/Finding.java

@@ -58,7 +58,6 @@ public class Finding extends DefectDojoModel {
   Long test;
 
   @JsonProperty
-  @NonNull
   String mitigation;
 
   @JsonProperty