Remove duplicate NB comment identifier from 4429

Author: jwakely

xml/issue4429.xml

@@ -12,7 +12,6 @@
 
 <discussion>
 <b>Addresses <a href="https://github.com/cplusplus/nbballot/issues/988">US 109-170</a></b>
-<b>Addresses US 109-170</b>
 <p>
 <sref ref="[meta.reflection.layout]"/> p#8
 This should similarly disallow data member descriptions of bit-fields.