internal and external link in same section break

[FranklinYu]

Steps to reproduce

1. In empty folder, create a file lib/test.rb with content

   # {#both} internal and {External}[http://www.rubydoc.info/] breaks.
   def both
     nil
   end
   
   # {#inner_only} works.
   def inner_only
     nil
   end
   
   # {External only}[http://www.rubydoc.info/] also works
   def external_only
     nil
   end

2. Run yard at project root.

Actual Output

The section for #both is rendered as

<a href="http://www.rubydoc.info/">#both} internal and {External</a>

(There is nothing interesting in console output, but I can surely provide it if you are interested in it.)

Expected Output

That section should be

<a href="#both-instance_method" title="#both (method)">#both</a>
internal and
<a href="http://www.rubydoc.info/">External</a>

Environment details:

• OS: macOS 10.12.5 (16F73)
• Ruby version: 2.4.1
• YARD version: 0.8.7.6
• Relevant software dependency/versions: N/A

• I have read the Contributing Guide.

[FranklinYu]

It is mentioned in #210 that the documentation is first translated by RDoc, who does not know the {#method} syntax. Since my documentation heavily rely on Yard functionality, supporting RDoc is impossible anyway (thus unnecessary), so I may as well just use Yard’s link (which works as expected).