Prevent confusing template errors when seq is nil
Prevent confusing template errors when seq is nil

The common is the `where` func and this:

```
panic: reflect: call of reflect.Value.Type on zero Value [recovered]
	panic: reflect: call of reflect.Value.Type on zero Value
```

soundrussian/hugo,mdhender/hugo,digitalcraftsman/hugo,anthonyfok/hugo,mdhender/hugo,tischda/hugo,mayah/hugo,coderzh/hugo,Zenithar/hugo,gohugoio/hugo,derekperkins/hugo,MarkDBlackwell/hugo,fedelibre/hugo,tischda/hugo,gohugoio/hugo,bogem/hugo,mayah/hugo,mitchchn/hugo,bogem/hugo,fedelibre/hugo,soundrussian/hugo,derekperkins/hugo,digitalcraftsman/hugo,gohugoio/hugo,sprig/hugo,abourget/hugo,vbatoufflet/hugo,ifraixedes/hugo,mitchchn/hugo,coderzh/hugo,tubo028/hugo,ifraixedes/hugo,sprig/hugo,melo/hugo,ffrizzo/hugo,abourget/hugo,vbatoufflet/hugo,tubo028/hugo,melo/hugo,jygastaud/hugo,MarkDBlackwell/hugo,Zenithar/hugo,mdhender/hugo,anthonyfok/hugo,anthonyfok/hugo,mdhender/hugo,fedelibre/hugo,ffrizzo/hugo,fedelibre/hugo,jygastaud/hugo