Update changelog with #57

Author: igaztanaga

doc/move.qbk

@@ -806,6 +806,7 @@ Special thanks to:
 
 *  Fixed bugs:
    *  [@https://github.com/boostorg/move/issues/56 Git Issue #56: ['"Forward declarations of std types cause compilation errors on some platforms"]].
+   *  [@https://github.com/boostorg/move/issues/57 Git Issue #57: ['"<boost/move/adl_move_swap.hpp> fails to compile under libc++-19"]].
 
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