FIX: Markdown formatting error

vendor/assets/javascripts/better_markdown.js

@@ -1354,6 +1354,7 @@
           // [links][] uses links as its reference
           attrs = { ref: ( m[ 1 ] || String(children) ).toLowerCase(),  original: orig.substr( 0, consumed ) };
 
+          if (children && children.length > 0) {
             link = [ "link_ref", attrs ].concat( children );
 
             // We can't check if the reference is known here as it likely wont be
@@ -1361,6 +1362,7 @@
             // Store the original so that conversion can revert if the ref isn't found.
             return [ consumed, link ];
           }
+        }
 
         // Another check for references
         m = orig.match(/^\s*\[(.*?)\]:\s*(\S+)(?:\s+(?:(['"])(.*?)\3|\((.*?)\)))?\n?/);