front: keep the '-' only if we have the second part

Signed-off-by: nncluzu <ngamenichaka@yahoo.fr>

Author: kmer2016

front/src/applications/stdcm/components/StdcmForm/StdcmConsist.tsx

@@ -72,8 +72,10 @@ const StdcmConsist = ({ disabled = false }: StdcmConfigCardProps) => {
     }
   }, [towedRollingStock]);
 
-  const getLabel = (rs: LightRollingStockWithLiveries) =>
-    `${rs.name} - ${rs.metadata?.series || rs.metadata?.reference || ''}`;
+  const getLabel = (rs: LightRollingStockWithLiveries) => {
+    const secondPart = rs.metadata?.series || rs.metadata?.reference || '';
+    return secondPart ? `${rs.name} - ${secondPart}` : rs.name;
+  };
 
   const onInputClick = () => {
     if (rollingStock?.id !== undefined) {