refs #4975 Minor changes

loopback/locale/es.json

@@ -250,5 +250,5 @@
 	"Receipt's bank was not found": "No se encontró el banco del recibo",
 	"This receipt was not compensated": "Este recibo no ha sido compensado",
 	"Client's email was not found": "No se encontró el email del cliente",
-	"Not exist this app name": "No existe este nombre de aplicación"
+	"App name does not exist": "El nombre de aplicación no es válido"
 }

modules/mdb/back/methods/mdbVersion/last.js

@@ -12,7 +12,7 @@ module.exports = Self => {
             }
         ],
         returns: {
-            type: ['object'],
+            type: 'number',
             root: true
         },
         http: {
@@ -24,11 +24,12 @@ module.exports = Self => {
     Self.last = async(ctx, appName) => {
         const models = Self.app.models;
         const versions = await models.MdbVersion.find({
-            where: {app: appName}
+            where: {app: appName},
+            fields: ['version']
         });
 
         if (!versions.length)
-            throw new UserError('Not exist this app name');
+            throw new UserError('App name does not exist');
 
         let maxNumber = 0;
         for (let mdb of versions) {