Fix Liquid Warning
Fix Liquid Warning

Using single quotes caused the following warning when using `jekyll serve`.
```
Liquid Warning: Liquid syntax error (line 7): Expected dotdot but found comparison in "(page.image.feature contains 'https') or (page.image.feature contains 'http')" in /_layouts/post.html
```
m4ng0n3l/m4ng0n3l.github.io,warden/warden.github.io,Althaire/althaire.github.io,warden/warden.github.io,kgarrett/kgarrett.github.io,dubbar/dubbar.github.io,m4ng0n3l/m4ng0n3l.github.io,xiaobing211314/xiaobing211314.github.io,RemziDalyan/leonids,ibabywang/babywang,kostistsaprailis/kostistsaprailis.github.io,fievelk/keenformatics,riydev/riydev.github.io,thechargedneutron/thechargedneutron.github.io,thechargedneutron/thechargedneutron.github.io,xiaobing211314/xiaobing211314.github.io,Althaire/althaire.github.io,kgarrett/kgarrett.github.io,fievelk/keenformatics,fievelk/keenformatics,xiaobing211314/xiaobing211314.github.io,RemziDalyan/leonids,dubbar/dubbar.github.io,jncpn/jncpn.github.io,renyuanz/leonids,riydev/riydev.github.io,jmssmth/jso,Althaire/althaire.github.io,jmssmth/jso,lavelee/blog,renyuanz/leonids,ibabywang/babywang,jmssmth/jso,jncpn/jncpn.github.io,kostistsaprailis/kostistsaprailis.github.io,thechargedneutron/thechargedneutron.github.io