Rodn search unige contributors

AoU-ResourceServerCommon/src/main/java/ch/unige/aou/service/rest/UnigePersonSearchService.java

@@ -37,7 +37,7 @@ public abstract class UnigePersonSearchService implements UnigePersonSearch {
    */
   protected void discardNotNecessaryYearsOfBirth(List<UnigePersonDTO> results) {
 
-    Map<Object, Long> fullnameOccurences = results.stream()
+    Map<String, Long> fullnameOccurences = results.stream()
             .collect(groupingBy(unigePersonDTO -> unigePersonDTO.getFirstname() + NAME_SEPARATOR + unigePersonDTO.getLastname(), counting()));
 
     results.stream().forEach(unigePersonDTO -> {