[over.best.ics] Fix a typo in "user-defined conversion sequence"

Author: Arcoth

source/overloading.tex

@@ -1824,7 +1824,7 @@
 \indextext{sequence!ambiguous conversion}%
 For the purpose of ranking implicit conversion sequences as described
 in~\ref{over.ics.rank}, the ambiguous conversion sequence is treated
-as a user-defined sequence that is indistinguishable from any
+as a user-defined conversion sequence that is indistinguishable from any
 other user-defined conversion sequence\footnote{The ambiguous conversion
 sequence is ranked with user-defined
 conversion sequences because multiple conversion sequences