feat(templating): set default min span to 4, fixes grafana#5662

Author: torkelo

public/app/features/dashboard/dynamic_dashboard_srv.ts

@@ -177,7 +177,7 @@ export class DynamicDashboardSrv {
 
     _.each(selected, (option, index) => {
       var copy = this.getPanelClone(panel, row, index);
-      copy.span = Math.max(12 / selected.length, panel.minSpan);
+      copy.span = Math.max(12 / selected.length, panel.minSpan || 4);
       copy.scopedVars = copy.scopedVars || {};
       copy.scopedVars[variable.name] = option;
     });