Bootstrap Navbar: subpage doesn't open on mobile, everything works fine on PC

I searched this on google but couldn't find this specific problem. I have created this website:

shahsaad.base.pk

The homepage is shahsaad.base.pk .. Then I created a video.html, aboutus.php files in the root directory. Then for photos, I created a folder photos in the root directory and in there I created an index.html file so that when it users go to http://ift.tt/1GXoamz the index file opens.

         <li><a href="http://ift.tt/1GLRZkA"> Photo Gallery</a></li>
         <li><a href="videos.html"> Videos</a></li>
         <li><a href=""> Notes</a></li>
         <li><a href="aboutus.php"> About us</a></li>
         <li><a href="" id="currentWeather"><span class="glyphicon glyphicon-cloud"></span></a></li>

My problem is with Photo Gallery link in the navbar on mobile devices. When I open the homepage with www prefix and then click Photo Gallery, it opens. BUT when I open my homepage without www prefix and then click Photo Gallery, nothing happens. All other links are working fine i.e video.html and aboutus.php which aren't in separate folder but in the root directory.

I tried changing

<li><a href="http://ift.tt/1GLRZkA"> Photo Gallery</a></li>

to

<li><a href="/photos"> Photo Gallery</a></li>

or

<li><a href="/photos/index.html"> Photo Gallery</a></li>

or

<li><a href="http://ift.tt/1GXo7qN"> Photo Gallery</a></li>

but that didn't work either.

Everything works fine on PC. Can someone please tell me whats the problem? I have finally given up after hours of banging my head with this.