SSDM-55: fixes after changes of properties map to <String, Serializable>

server-screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/WellContentDialog.java

@@ -501,7 +501,7 @@ public class WellContentDialog extends ImageDialog
         {
             if (prop.getPropertyType().getCode().equalsIgnoreCase(ScreeningConstants.GENE_SYMBOLS))
             {
-                return prop.getValue();
+                return prop.tryGetAsString();
             }
         }
         return null;

server-screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/LibraryRegistrationTask.java

@@ -196,7 +196,7 @@ class LibraryRegistrationTask implements IASyncAction
             return;
         }
 
-        String existingGene = existingGeneProp.getValue();
+        String existingGene = existingGeneProp.tryGetAsString();
 
         IEntityProperty newGeneProp =
                 EntityHelper.tryFindProperty(newMaterial.getProperties(),
@@ -207,7 +207,7 @@ class LibraryRegistrationTask implements IASyncAction
             return;
         }
 
-        String mergedGeneSymbols = mergeGeneSymbols(existingGene, newGeneProp.getValue());
+        String mergedGeneSymbols = mergeGeneSymbols(existingGene, newGeneProp.tryGetAsString());
         newGeneProp.setValue(mergedGeneSymbols);
     }