Update bip-0049.mediawiki

Fix broken internal link

Author: torkelrogstad

bip-0049.mediawiki

@@ -68,7 +68,7 @@ To derive the P2SH address from the above calculated public key, we use the enca
 
 ==Backwards Compatibility==
 
-This BIP is not backwards compatible by design as described under [#considerations]. An incompatible wallet will not discover accounts at all and the user will notice that something is wrong.
+This BIP is not backwards compatible by design as described under [[#considerations|considerations]]. An incompatible wallet will not discover accounts at all and the user will notice that something is wrong.
 
 
 ==Test vectors==