Templating: Correctly display __text in multi-values variable after refresh (#17918)

Fixes: #17915 - Templating: __value's are displayed instead of __text's after variable is updated

public/app/features/templating/variable_srv.ts

@@ -194,7 +194,7 @@ export class VariableSrv {
           }),
           text: _.map(selected, val => {
             return val.text;
-          }).join(' + '),
+          }),
         };
       }