fix: updating foreign keys when adding new entity to the db

MyINPulse-back/src/main/java/enseirb/myinpulse/service/database/ProjectService.java

@@ -91,7 +91,7 @@ public class ProjectService {
         }
 
         if (administrator != null) {
-            project.get().setAdministrator(administrator);
+            project.get().setProjectAdministrator(administrator);
         }
 
         return this.projectRepository.save(project.get());