Check for instanceof Title

[mwjames]

Mail from Cicalese, Cindy:

Tested on MediaWiki 1.21 and 1.22 throws PHP Fatal error: Call to a member function isSpecialPage() on a non-object in …/mediawiki/extensions/SemanticResultFormats/formats/tagcloud/TagCloud.php on line 80

I get this error if I include any tagcloud in my wiki. An example is the following:

{{#ask:[[Tags::+]]
|?Tags
|format=tagcloud
|template=TagTagCloud
|maxtags=75
|limit=10000
}}

[mwjames]

Caused by the RequestContext returning a null instead of a Title object.

[cicalese]

Thank you! I have confirmed that this fix corrects the error.

[formwandler]

I can also confirm that this fixed my update problems on PHP 5.3.3.