Inconsistent URL and Wiki links consealing in vimwiki and markdown

[citrin]

g:vimwiki_url_maxsave option works differently in vimwiki default syntax and markdown.

When markdown is used g:vimwiki_url_maxsave = 0 prevent URL (http:// etc.) shortening, but wiki links with a title, like [Title](page) are still show as Title. This is desired behavior.

With default syntax setting g:vimwiki_url_maxsave = 0 not only prevents shortening raw URLs but also prevents replacing [[page|Tile]] with Title. I think that g:vimwiki_url_maxsave = 0 shouldn't prevent wikilink concealing. If anybody what to see raw markup, then g:vimwiki_conceallevel = 0 can be used for this.

If you like this change I can make a pull request.