Fixes broken mediawiki link

Author: EthanHeilman

bip-???-cat.mediawiki

@@ -61,7 +61,7 @@ The value of <code>MAX_SCRIPT_ELEMENT_SIZE</code> is 520.
 
 ==Notes==
 
-[OP_CAT as it existed in the Bitcoin codebase](https://github.com/bitcoin/bitcoin/blob/01cd2fdaf3ac6071304ceb80fb7436ac02b1059e/script.cpp#L381-L393) prior to the commit "misc changes" 4bd188c<ref>S. Nakamoto, "misc changes", Aug 25 2010, https://github.com/bitcoin/bitcoin/commit/4bd188c4383d6e614e18f79dc337fbabe8464c82#diff-27496895958ca30c47bbb873299a2ad7a7ea1003a9faa96b317250e3b7aa1fefR94</ref> which disabled it:
+[https://github.com/bitcoin/bitcoin/blob/01cd2fdaf3ac6071304ceb80fb7436ac02b1059e/script.cpp#L381-L393 OP_CAT as it existed in the Bitcoin codebase] prior to the commit "misc changes" 4bd188c<ref>S. Nakamoto, "misc changes", Aug 25 2010, https://github.com/bitcoin/bitcoin/commit/4bd188c4383d6e614e18f79dc337fbabe8464c82#diff-27496895958ca30c47bbb873299a2ad7a7ea1003a9faa96b317250e3b7aa1fefR94</ref> which disabled it:
 
 <pre>
   // (x1 x2 -- out)